diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index c93eef5b065..5fe5027978c 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -2578,7 +2578,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
                             operand = (<TypeAssertion | NonNullExpression>operand).expression;
                         }
 
-                        // We have an expression of the form: (<Type>SubExpr)
+                        // We have an expression of the form: (<Type>SubExpr) or (SubExpr as Type)
                         // Emitting this as (SubExpr) is really not desirable. We would like to emit the subexpr as is.
                         // Omitting the parentheses, however, could cause change in the semantics of the generated
                         // code if the casted expression has a lower precedence than the rest of the expression, e.g.:
@@ -2592,6 +2592,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
                             operand.kind !== SyntaxKind.DeleteExpression &&
                             operand.kind !== SyntaxKind.PostfixUnaryExpression &&
                             operand.kind !== SyntaxKind.NewExpression &&
+                            !(operand.kind === SyntaxKind.BinaryExpression && node.expression.kind === SyntaxKind.AsExpression) &&
                             !(operand.kind === SyntaxKind.CallExpression && node.parent.kind === SyntaxKind.NewExpression) &&
                             !(operand.kind === SyntaxKind.FunctionExpression && node.parent.kind === SyntaxKind.CallExpression) &&
                             !(operand.kind === SyntaxKind.NumericLiteral && node.parent.kind === SyntaxKind.PropertyAccessExpression)) {
diff --git a/tests/baselines/reference/asOpEmitParens.js b/tests/baselines/reference/asOpEmitParens.js
new file mode 100644
index 00000000000..dee8d263eae
--- /dev/null
+++ b/tests/baselines/reference/asOpEmitParens.js
@@ -0,0 +1,19 @@
+//// [asOpEmitParens.ts]
+declare var x;
+// Must emit as (x + 1) * 3
+(x + 1 as number) * 3;
+
+// Should still emit as x.y
+(x as any).y;
+
+// Emit as new (x())
+new (x() as any);
+
+
+//// [asOpEmitParens.js]
+// Must emit as (x + 1) * 3
+(x + 1) * 3;
+// Should still emit as x.y
+x.y;
+// Emit as new (x())
+new (x());
diff --git a/tests/baselines/reference/asOpEmitParens.symbols b/tests/baselines/reference/asOpEmitParens.symbols
new file mode 100644
index 00000000000..210d9f3ea0d
--- /dev/null
+++ b/tests/baselines/reference/asOpEmitParens.symbols
@@ -0,0 +1,16 @@
+=== tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts ===
+declare var x;
+>x : Symbol(x, Decl(asOpEmitParens.ts, 0, 11))
+
+// Must emit as (x + 1) * 3
+(x + 1 as number) * 3;
+>x : Symbol(x, Decl(asOpEmitParens.ts, 0, 11))
+
+// Should still emit as x.y
+(x as any).y;
+>x : Symbol(x, Decl(asOpEmitParens.ts, 0, 11))
+
+// Emit as new (x())
+new (x() as any);
+>x : Symbol(x, Decl(asOpEmitParens.ts, 0, 11))
+
diff --git a/tests/baselines/reference/asOpEmitParens.types b/tests/baselines/reference/asOpEmitParens.types
new file mode 100644
index 00000000000..b87d7f4d91f
--- /dev/null
+++ b/tests/baselines/reference/asOpEmitParens.types
@@ -0,0 +1,30 @@
+=== tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts ===
+declare var x;
+>x : any
+
+// Must emit as (x + 1) * 3
+(x + 1 as number) * 3;
+>(x + 1 as number) * 3 : number
+>(x + 1 as number) : number
+>x + 1 as number : number
+>x + 1 : any
+>x : any
+>1 : number
+>3 : number
+
+// Should still emit as x.y
+(x as any).y;
+>(x as any).y : any
+>(x as any) : any
+>x as any : any
+>x : any
+>y : any
+
+// Emit as new (x())
+new (x() as any);
+>new (x() as any) : any
+>(x() as any) : any
+>x() as any : any
+>x() : any
+>x : any
+
diff --git a/tests/baselines/reference/umdGlobalMerge.errors.txt b/tests/baselines/reference/umdGlobalMerge.errors.txt
deleted file mode 100644
index eb4a116ef09..00000000000
--- a/tests/baselines/reference/umdGlobalMerge.errors.txt
+++ /dev/null
@@ -1,20 +0,0 @@
-tests/cases/compiler/b.d.ts(2,20): error TS2305: Module '"tests/cases/compiler/a".ns' has no exported member 'IFoo'.
-
-
-==== tests/cases/compiler/a.d.ts (0 errors) ====
-    export = ns;
-    
-    export as namespace ns;
-    
-    declare namespace ns {
-      export var x: number;
-      export interface IFoo { }
-    }
-    
-==== tests/cases/compiler/b.d.ts (1 errors) ====
-    declare namespace ns.something {
-      export var p: ns.IFoo;
-                       ~~~~
-!!! error TS2305: Module '"tests/cases/compiler/a".ns' has no exported member 'IFoo'.
-    }
-    
\ No newline at end of file
diff --git a/tests/cases/compiler/umdGlobalMerge.ts b/tests/cases/compiler/umdGlobalMerge.ts
deleted file mode 100644
index 1f42e2fda71..00000000000
--- a/tests/cases/compiler/umdGlobalMerge.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-// @filename: a.d.ts
-export = ns;
-
-export as namespace ns;
-
-declare namespace ns {
-  export var x: number;
-  export interface IFoo { }
-}
-
-// @filename: b.d.ts
-declare namespace ns.something {
-  export var p: ns.IFoo;
-}
diff --git a/tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts b/tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts
new file mode 100644
index 00000000000..7a97a74168a
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOpEmitParens.ts
@@ -0,0 +1,9 @@
+declare var x;
+// Must emit as (x + 1) * 3
+(x + 1 as number) * 3;
+
+// Should still emit as x.y
+(x as any).y;
+
+// Emit as new (x())
+new (x() as any);