diff --git a/tests/baselines/reference/constDeclarations-access.errors.txt b/tests/baselines/reference/constDeclarations-access.errors.txt
index 04b942aec09..3c748cc4a5f 100644
--- a/tests/baselines/reference/constDeclarations-access.errors.txt
+++ b/tests/baselines/reference/constDeclarations-access.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/compiler/file2.ts(1,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
+tests/cases/compiler/file2.ts(1,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
 
 
 ==== tests/cases/compiler/file1.ts (0 errors) ====
@@ -8,4 +8,4 @@ tests/cases/compiler/file2.ts(1,1): error TS2449: The operand of an increment or
 ==== tests/cases/compiler/file2.ts (1 errors) ====
     x++;
     ~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
\ No newline at end of file
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
\ No newline at end of file
diff --git a/tests/baselines/reference/constDeclarations-access2.errors.txt b/tests/baselines/reference/constDeclarations-access2.errors.txt
index 6a360e11014..667f490a374 100644
--- a/tests/baselines/reference/constDeclarations-access2.errors.txt
+++ b/tests/baselines/reference/constDeclarations-access2.errors.txt
@@ -1,20 +1,20 @@
-tests/cases/compiler/constDeclarations-access2.ts(5,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(6,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(7,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(18,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(19,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(20,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(21,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access2.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
+tests/cases/compiler/constDeclarations-access2.ts(5,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(6,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(7,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(18,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(19,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(20,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(21,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access2.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
 
 
 ==== tests/cases/compiler/constDeclarations-access2.ts (17 errors) ====
@@ -24,57 +24,57 @@ tests/cases/compiler/constDeclarations-access2.ts(23,3): error TS2449: The opera
     // Errors
     x = 1;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x += 2;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x -= 3;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x *= 4;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x /= 5;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x %= 6;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x <<= 7;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x >>= 8;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x >>>= 9;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x &= 10;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x |= 11;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     x ^= 12;
     ~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     x++;
     ~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     x--;
     ~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     ++x;
       ~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     --x;
       ~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     ++((x));
       ~~~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     // OK
     var a = x + 1;
diff --git a/tests/baselines/reference/constDeclarations-access3.errors.txt b/tests/baselines/reference/constDeclarations-access3.errors.txt
index 577b087dff0..a6cb124d28c 100644
--- a/tests/baselines/reference/constDeclarations-access3.errors.txt
+++ b/tests/baselines/reference/constDeclarations-access3.errors.txt
@@ -1,21 +1,21 @@
-tests/cases/compiler/constDeclarations-access3.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(17,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(18,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(19,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(21,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(22,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(24,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(26,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access3.ts(28,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
+tests/cases/compiler/constDeclarations-access3.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(17,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(18,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(19,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(21,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(22,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(24,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(26,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access3.ts(28,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
 
 
 ==== tests/cases/compiler/constDeclarations-access3.ts (18 errors) ====
@@ -28,61 +28,61 @@ tests/cases/compiler/constDeclarations-access3.ts(28,1): error TS2450: Left-hand
     // Errors
     M.x = 1;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x += 2;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x -= 3;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x *= 4;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x /= 5;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x %= 6;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x <<= 7;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x >>= 8;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x >>>= 9;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x &= 10;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x |= 11;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x ^= 12;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     M.x++;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     M.x--;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     ++M.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     --M.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     ++((M.x));
       ~~~~~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     M["x"] = 0;
     ~~~~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     // OK
     var a = M.x + 1;
diff --git a/tests/baselines/reference/constDeclarations-access4.errors.txt b/tests/baselines/reference/constDeclarations-access4.errors.txt
index 9745c0d2624..3d7d4a704a8 100644
--- a/tests/baselines/reference/constDeclarations-access4.errors.txt
+++ b/tests/baselines/reference/constDeclarations-access4.errors.txt
@@ -1,21 +1,21 @@
-tests/cases/compiler/constDeclarations-access4.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(17,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(18,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(19,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(21,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(22,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(24,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(26,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations-access4.ts(28,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
+tests/cases/compiler/constDeclarations-access4.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(16,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(17,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(18,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(19,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(21,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(22,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(23,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(24,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(26,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations-access4.ts(28,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
 
 
 ==== tests/cases/compiler/constDeclarations-access4.ts (18 errors) ====
@@ -28,61 +28,61 @@ tests/cases/compiler/constDeclarations-access4.ts(28,1): error TS2450: Left-hand
     // Errors
     M.x = 1;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x += 2;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x -= 3;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x *= 4;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x /= 5;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x %= 6;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x <<= 7;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x >>= 8;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x >>>= 9;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x &= 10;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x |= 11;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     M.x ^= 12;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     M.x++;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     M.x--;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     ++M.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     --M.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     ++((M.x));
       ~~~~~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     M["x"] = 0;
     ~~~~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     // OK
     var a = M.x + 1;
diff --git a/tests/baselines/reference/constDeclarations-access5.errors.txt b/tests/baselines/reference/constDeclarations-access5.errors.txt
index 23200e50ee4..45160bbc7ce 100644
--- a/tests/baselines/reference/constDeclarations-access5.errors.txt
+++ b/tests/baselines/reference/constDeclarations-access5.errors.txt
@@ -1,21 +1,21 @@
-tests/cases/compiler/constDeclarations_access_2.ts(4,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(5,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(6,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(7,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(17,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(18,1): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(19,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(20,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(22,3): error TS2449: The operand of an increment or decrement operator cannot be a constant.
-tests/cases/compiler/constDeclarations_access_2.ts(24,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
+tests/cases/compiler/constDeclarations_access_2.ts(4,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(5,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(6,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(7,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(8,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(9,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(10,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(11,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(12,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(13,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(14,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(15,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(17,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(18,1): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(19,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(20,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(22,3): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
+tests/cases/compiler/constDeclarations_access_2.ts(24,1): error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
 
 
 ==== tests/cases/compiler/constDeclarations_access_2.ts (18 errors) ====
@@ -24,61 +24,61 @@ tests/cases/compiler/constDeclarations_access_2.ts(24,1): error TS2450: Left-han
     // Errors
     m.x = 1;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x += 2;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x -= 3;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x *= 4;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x /= 5;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x %= 6;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x <<= 7;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x >>= 8;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x >>>= 9;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x &= 10;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x |= 11;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m.x ^= 12;
     ~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     m
     m.x++;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     m.x--;
     ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     ++m.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     --m.x;
       ~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     ++((m.x));
       ~~~~~~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     m["x"] = 0;
     ~~~~~~
-!!! error TS2450: Left-hand side of assignment expression cannot be a constant.
+!!! error TS2450: Left-hand side of assignment expression cannot be a constant or a read-only property.
     
     // OK
     var a = m.x + 1;
diff --git a/tests/baselines/reference/constDeclarations-errors.errors.txt b/tests/baselines/reference/constDeclarations-errors.errors.txt
index 10501beb1a5..98b12b616f7 100644
--- a/tests/baselines/reference/constDeclarations-errors.errors.txt
+++ b/tests/baselines/reference/constDeclarations-errors.errors.txt
@@ -4,7 +4,7 @@ tests/cases/compiler/constDeclarations-errors.ts(5,7): error TS1155: 'const' dec
 tests/cases/compiler/constDeclarations-errors.ts(5,11): error TS1155: 'const' declarations must be initialized
 tests/cases/compiler/constDeclarations-errors.ts(5,15): error TS1155: 'const' declarations must be initialized
 tests/cases/compiler/constDeclarations-errors.ts(5,27): error TS1155: 'const' declarations must be initialized
-tests/cases/compiler/constDeclarations-errors.ts(10,27): error TS2449: The operand of an increment or decrement operator cannot be a constant.
+tests/cases/compiler/constDeclarations-errors.ts(10,27): error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
 tests/cases/compiler/constDeclarations-errors.ts(13,11): error TS1155: 'const' declarations must be initialized
 tests/cases/compiler/constDeclarations-errors.ts(16,20): error TS1155: 'const' declarations must be initialized
 
@@ -33,7 +33,7 @@ tests/cases/compiler/constDeclarations-errors.ts(16,20): error TS1155: 'const' d
     // error, assigning to a const
     for(const c8 = 0; c8 < 1; c8++) { }
                               ~~
-!!! error TS2449: The operand of an increment or decrement operator cannot be a constant.
+!!! error TS2449: The operand of an increment or decrement operator cannot be a constant or a read-only property.
     
     // error, can not be unintalized
     for(const c9; c9 < 1;) { }
diff --git a/tests/baselines/reference/for-of2.errors.txt b/tests/baselines/reference/for-of2.errors.txt
index 0b5133cde13..f4f39f60f67 100644
--- a/tests/baselines/reference/for-of2.errors.txt
+++ b/tests/baselines/reference/for-of2.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/for-ofStatements/for-of2.ts(1,7): error TS1155: 'const' declarations must be initialized
-tests/cases/conformance/es6/for-ofStatements/for-of2.ts(2,6): error TS2485: The left-hand side of a 'for...of' statement cannot be a previously defined constant.
+tests/cases/conformance/es6/for-ofStatements/for-of2.ts(2,6): error TS2485: The left-hand side of a 'for...of' statement cannot be a constant or a read-only property.
 
 
 ==== tests/cases/conformance/es6/for-ofStatements/for-of2.ts (2 errors) ====
@@ -8,4 +8,4 @@ tests/cases/conformance/es6/for-ofStatements/for-of2.ts(2,6): error TS2485: The
 !!! error TS1155: 'const' declarations must be initialized
     for (v of []) { }
          ~
-!!! error TS2485: The left-hand side of a 'for...of' statement cannot be a previously defined constant.
\ No newline at end of file
+!!! error TS2485: The left-hand side of a 'for...of' statement cannot be a constant or a read-only property.
\ No newline at end of file