diff --git a/tests/baselines/reference/ambientEnumDeclaration1.errors.txt b/tests/baselines/reference/ambientEnumDeclaration1.errors.txt
new file mode 100644
index 00000000000..419f7e184ac
--- /dev/null
+++ b/tests/baselines/reference/ambientEnumDeclaration1.errors.txt
@@ -0,0 +1,24 @@
+tests/cases/conformance/ambient/ambientEnumDeclaration1.ts(5,5): error TS1066: Ambient enum elements can only have integer literal initializers.
+tests/cases/conformance/ambient/ambientEnumDeclaration1.ts(6,5): error TS1066: Ambient enum elements can only have integer literal initializers.
+tests/cases/conformance/ambient/ambientEnumDeclaration1.ts(7,5): error TS1066: Ambient enum elements can only have integer literal initializers.
+tests/cases/conformance/ambient/ambientEnumDeclaration1.ts(8,5): error TS1066: Ambient enum elements can only have integer literal initializers.
+
+
+==== tests/cases/conformance/ambient/ambientEnumDeclaration1.ts (4 errors) ====
+    // In ambient enum declarations, all values specified in enum member declarations must be classified as constant enum expressions.
+    
+    declare enum E {
+        a = 10,
+        b = 10 + 1,
+        ~
+!!! error TS1066: Ambient enum elements can only have integer literal initializers.
+        c = b,
+        ~
+!!! error TS1066: Ambient enum elements can only have integer literal initializers.
+        d = (c) + 1,
+        ~
+!!! error TS1066: Ambient enum elements can only have integer literal initializers.
+        e = 10 << 2 * 8,
+        ~
+!!! error TS1066: Ambient enum elements can only have integer literal initializers.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/ambientEnumDeclaration1.js b/tests/baselines/reference/ambientEnumDeclaration1.js
new file mode 100644
index 00000000000..dcdb100e906
--- /dev/null
+++ b/tests/baselines/reference/ambientEnumDeclaration1.js
@@ -0,0 +1,13 @@
+//// [ambientEnumDeclaration1.ts]
+// In ambient enum declarations, all values specified in enum member declarations must be classified as constant enum expressions.
+
+declare enum E {
+    a = 10,
+    b = 10 + 1,
+    c = b,
+    d = (c) + 1,
+    e = 10 << 2 * 8,
+}
+
+//// [ambientEnumDeclaration1.js]
+// In ambient enum declarations, all values specified in enum member declarations must be classified as constant enum expressions.
diff --git a/tests/baselines/reference/ambientEnumDeclaration2.js b/tests/baselines/reference/ambientEnumDeclaration2.js
new file mode 100644
index 00000000000..8ef6facfe6d
--- /dev/null
+++ b/tests/baselines/reference/ambientEnumDeclaration2.js
@@ -0,0 +1,17 @@
+//// [ambientEnumDeclaration2.ts]
+// In ambient enum declarations that specify no const modifier, enum member declarations
+// that omit a value are considered computed members (as opposed to having auto- incremented values assigned).
+
+declare enum E {
+    a, // E.a
+    b, // E.b
+}
+
+declare const enum E1 {
+    a, // E.a = 0
+    b, // E.b = 1
+}
+
+//// [ambientEnumDeclaration2.js]
+// In ambient enum declarations that specify no const modifier, enum member declarations
+// that omit a value are considered computed members (as opposed to having auto- incremented values assigned).
diff --git a/tests/baselines/reference/ambientEnumDeclaration2.types b/tests/baselines/reference/ambientEnumDeclaration2.types
new file mode 100644
index 00000000000..2c87066b7fa
--- /dev/null
+++ b/tests/baselines/reference/ambientEnumDeclaration2.types
@@ -0,0 +1,23 @@
+=== tests/cases/conformance/ambient/ambientEnumDeclaration2.ts ===
+// In ambient enum declarations that specify no const modifier, enum member declarations
+// that omit a value are considered computed members (as opposed to having auto- incremented values assigned).
+
+declare enum E {
+>E : E, Symbol(E, Decl(ambientEnumDeclaration2.ts, 0, 0))
+
+    a, // E.a
+>a : E, Symbol(E.a, Decl(ambientEnumDeclaration2.ts, 3, 16))
+
+    b, // E.b
+>b : E, Symbol(E.b, Decl(ambientEnumDeclaration2.ts, 4, 6))
+}
+
+declare const enum E1 {
+>E1 : E1, Symbol(E1, Decl(ambientEnumDeclaration2.ts, 6, 1))
+
+    a, // E.a = 0
+>a : E1, Symbol(E1.a, Decl(ambientEnumDeclaration2.ts, 8, 23))
+
+    b, // E.b = 1
+>b : E1, Symbol(E1.b, Decl(ambientEnumDeclaration2.ts, 9, 6))
+}
diff --git a/tests/cases/conformance/ambient/ambientEnumDeclaration1.ts b/tests/cases/conformance/ambient/ambientEnumDeclaration1.ts
new file mode 100644
index 00000000000..9cafe943d13
--- /dev/null
+++ b/tests/cases/conformance/ambient/ambientEnumDeclaration1.ts
@@ -0,0 +1,9 @@
+// In ambient enum declarations, all values specified in enum member declarations must be classified as constant enum expressions.
+
+declare enum E {
+    a = 10,
+    b = 10 + 1,
+    c = b,
+    d = (c) + 1,
+    e = 10 << 2 * 8,
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/ambient/ambientEnumDeclaration2.ts b/tests/cases/conformance/ambient/ambientEnumDeclaration2.ts
new file mode 100644
index 00000000000..dd6e1a1605e
--- /dev/null
+++ b/tests/cases/conformance/ambient/ambientEnumDeclaration2.ts
@@ -0,0 +1,12 @@
+// In ambient enum declarations that specify no const modifier, enum member declarations
+// that omit a value are considered computed members (as opposed to having auto- incremented values assigned).
+
+declare enum E {
+    a, // E.a
+    b, // E.b
+}
+
+declare const enum E1 {
+    a, // E.a = 0
+    b, // E.b = 1
+}
\ No newline at end of file