diff --git a/tests/cases/fourslash/getEmitOutputSingleFile2.ts b/tests/cases/fourslash/getEmitOutputSingleFile2.ts
index bcb1012a6ea..8bf4f7f4af7 100644
--- a/tests/cases/fourslash/getEmitOutputSingleFile2.ts
+++ b/tests/cases/fourslash/getEmitOutputSingleFile2.ts
@@ -1,6 +1,7 @@
 /// <reference path="fourslash.ts" />
 
 // @BaselineFile: getEmitOutputSingleFile2.baseline
+// @module: CommonJS
 // @declaration: true
 // @out: declSingleFile.js
 // @outDir: tests/cases/fourslash/
diff --git a/tests/cases/fourslash/getEmitOutputWithDeclarationFile2.ts b/tests/cases/fourslash/getEmitOutputWithDeclarationFile2.ts
index f80fa777296..ac68611246b 100644
--- a/tests/cases/fourslash/getEmitOutputWithDeclarationFile2.ts
+++ b/tests/cases/fourslash/getEmitOutputWithDeclarationFile2.ts
@@ -1,6 +1,7 @@
 /// <reference path="fourslash.ts" />
 
 // @BaselineFile: getEmitOutputWithDeclarationFile2.baseline
+// @module: CommonJS
 
 // @Filename: decl.d.ts
 // @emitThisFile: true
diff --git a/tests/cases/fourslash/getSemanticDiagnosticForDeclaration.ts b/tests/cases/fourslash/getSemanticDiagnosticForDeclaration.ts
index fbd086d191d..6345c464213 100644
--- a/tests/cases/fourslash/getSemanticDiagnosticForDeclaration.ts
+++ b/tests/cases/fourslash/getSemanticDiagnosticForDeclaration.ts
@@ -1,5 +1,6 @@
 /// <reference path="fourslash.ts" />
 
+// @module: CommonJS
 // @declaration: true
 //// interface privateInterface {}
 //// export class Bar implements /*1*/privateInterface/*2*/{ }
diff --git a/tests/cases/fourslash/getSemanticDiagnosticForNoDeclaration.ts b/tests/cases/fourslash/getSemanticDiagnosticForNoDeclaration.ts
index 57a490fb31c..dc351a21f2c 100644
--- a/tests/cases/fourslash/getSemanticDiagnosticForNoDeclaration.ts
+++ b/tests/cases/fourslash/getSemanticDiagnosticForNoDeclaration.ts
@@ -1,5 +1,7 @@
 /// <reference path="fourslash.ts" />
 
+// @module: CommonJS
+
 //// interface privateInterface {}
 //// export class Bar implements /*1*/privateInterface/*2*/{ }
 
diff --git a/tests/cases/fourslash/underscoreTyping1.ts b/tests/cases/fourslash/underscoreTyping1.ts
index d4556e07f74..fddafe5e88e 100644
--- a/tests/cases/fourslash/underscoreTyping1.ts
+++ b/tests/cases/fourslash/underscoreTyping1.ts
@@ -1,4 +1,6 @@
 /// <reference path="fourslash.ts" />
+
+// @module: CommonJS
 
 //// interface Dictionary<T> {
 ////     [x: string]: T;