diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 0685eb44304..a222aa6a344 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -2302,7 +2302,7 @@
         "category": "Message",
         "code": 6081
     },
-    "Only 'amd', 'umd', and 'system' modules are supported alongside --{0}.": {
+    "Only 'amd' and 'system' modules are supported alongside --{0}.": {
         "category": "Error",
         "code": 6082
     },
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 7e4a1714d51..4ce0a39eb07 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -457,11 +457,11 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
             };
 
             let bundleEmitDelegates: Map<(node: SourceFile, startIndex: number, resolvePath?: boolean) => void> = {
-                [ModuleKind.ES6]() { },
+                [ModuleKind.ES6]() {},
                 [ModuleKind.AMD]: emitAMDModule,
                 [ModuleKind.System]: emitSystemModule,
-                [ModuleKind.UMD]: emitUMDModule,
-                [ModuleKind.CommonJS]() { },
+                [ModuleKind.UMD]() {},
+                [ModuleKind.CommonJS]() {},
             };
 
             if (compilerOptions.sourceMap || compilerOptions.inlineSourceMap) {
@@ -6827,11 +6827,11 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                 emitExportEquals(/*emitAsReturn*/ false);
             }
 
-            function emitUMDModule(node: SourceFile, startIndex: number, resolvePath?: boolean) {
+            function emitUMDModule(node: SourceFile, startIndex: number) {
                 emitEmitHelpers(node);
                 collectExternalModuleInfo(node);
 
-                let dependencyNames = getAMDDependencyNames(node, /*includeNonAmdDependencies*/ false, resolvePath);
+                let dependencyNames = getAMDDependencyNames(node, /*includeNonAmdDependencies*/ false);
 
                 // Module is detected first to support Browserify users that load into a browser with an AMD loader
                 writeLines(`(function (factory) {
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 163ddfa36c1..0cdcddbb0ed 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1064,8 +1064,8 @@ namespace ts {
             }
 
             // Cannot specify module gen that isn't amd, umd, or system with --out
-            if (outFile && options.module && options.module !== ModuleKind.AMD && options.module !== ModuleKind.UMD && options.module !== ModuleKind.System) {
-                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Only_amd_umd_and_system_modules_are_supported_alongside_0, options.out ? "out" : "outFile"));
+            if (outFile && options.module && options.module !== ModuleKind.AMD && options.module !== ModuleKind.System) {
+                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Only_amd_and_system_modules_are_supported_alongside_0, options.out ? "out" : "outFile"));
             }
 
             if (options.noEmit) {
diff --git a/tests/cases/compiler/outModuleConcatAmd.ts b/tests/cases/compiler/outModuleConcatAmd.ts
new file mode 100644
index 00000000000..411a13e72a2
--- /dev/null
+++ b/tests/cases/compiler/outModuleConcatAmd.ts
@@ -0,0 +1,12 @@
+// @target: ES5
+// @sourcemap: true
+// @declaration: true
+// @module: amd
+// @outFile: all.js
+
+// @Filename: ref/a.ts
+export class A { }
+
+// @Filename: b.ts
+import {A} from "./ref/a";
+export class B extends A { }
\ No newline at end of file
diff --git a/tests/cases/compiler/outModuleConcatCommonjs.ts b/tests/cases/compiler/outModuleConcatCommonjs.ts
new file mode 100644
index 00000000000..0cb57bd11e7
--- /dev/null
+++ b/tests/cases/compiler/outModuleConcatCommonjs.ts
@@ -0,0 +1,14 @@
+// @target: ES5
+// @sourcemap: true
+// @declaration: true
+// @module: commonjs
+// @outFile: all.js
+
+// This should be an error
+
+// @Filename: ref/a.ts
+export class A { }
+
+// @Filename: b.ts
+import {A} from "./ref/a";
+export class B extends A { }
\ No newline at end of file
diff --git a/tests/cases/compiler/outModuleConcatES6.ts b/tests/cases/compiler/outModuleConcatES6.ts
new file mode 100644
index 00000000000..e98514e9adc
--- /dev/null
+++ b/tests/cases/compiler/outModuleConcatES6.ts
@@ -0,0 +1,14 @@
+// @target: ES6
+// @sourcemap: true
+// @declaration: true
+// @module: es6
+// @outFile: all.js
+
+// This should be an error
+
+// @Filename: ref/a.ts
+export class A { }
+
+// @Filename: b.ts
+import {A} from "./ref/a";
+export class B extends A { }
\ No newline at end of file
diff --git a/tests/cases/compiler/outModuleConcatSystem.ts b/tests/cases/compiler/outModuleConcatSystem.ts
new file mode 100644
index 00000000000..c8d9b4e9737
--- /dev/null
+++ b/tests/cases/compiler/outModuleConcatSystem.ts
@@ -0,0 +1,12 @@
+// @target: ES5
+// @sourcemap: true
+// @declaration: true
+// @module: system
+// @outFile: all.js
+
+// @Filename: ref/a.ts
+export class A { }
+
+// @Filename: b.ts
+import {A} from "./ref/a";
+export class B extends A { }
\ No newline at end of file
diff --git a/tests/cases/compiler/outModuleConcatUmd.ts b/tests/cases/compiler/outModuleConcatUmd.ts
new file mode 100644
index 00000000000..fa4a4a519c6
--- /dev/null
+++ b/tests/cases/compiler/outModuleConcatUmd.ts
@@ -0,0 +1,14 @@
+// @target: ES5
+// @sourcemap: true
+// @declaration: true
+// @module: umd
+// @outFile: all.js
+
+// This should error
+
+// @Filename: ref/a.ts
+export class A { }
+
+// @Filename: b.ts
+import {A} from "./ref/a";
+export class B extends A { }
\ No newline at end of file