diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index c380a39611d..14aeb35dc89 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -1,4 +1,4 @@
-/// <reference path="types.ts"/>
+/// <reference path="types.ts"/>
 /// <reference path="performance.ts" />
 
 namespace ts {
@@ -2360,4 +2360,8 @@ namespace ts {
             return Extension.Jsx;
         }
     }
+
+    export function isCheckJsEnabledForFile(sourceFile: SourceFile, compilerOptions: CompilerOptions) {
+        return sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : compilerOptions.checkJs;
+    }
 }
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index bdc8f76cf60..8f1bd4ba36e 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1,4 +1,4 @@
-/// <reference path="sys.ts" />
+/// <reference path="sys.ts" />
 /// <reference path="emitter.ts" />
 /// <reference path="core.ts" />
 
@@ -918,8 +918,7 @@ namespace ts {
                 Debug.assert(!!sourceFile.bindDiagnostics);
                 const bindDiagnostics = sourceFile.bindDiagnostics;
                 // For JavaScript files, we don't want to report semantic errors unless explicitly requested.
-                const includeCheckDiagnostics = !isSourceFileJavaScript(sourceFile) ||
-                    (sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : options.checkJs);
+                const includeCheckDiagnostics = !isSourceFileJavaScript(sourceFile) || isCheckJsEnabledForFile(sourceFile, options);
                 const checkDiagnostics = includeCheckDiagnostics ? typeChecker.getDiagnostics(sourceFile, cancellationToken) : [];
                 const fileProcessingDiagnosticsInFile = fileProcessingDiagnostics.getDiagnostics(sourceFile.fileName);
                 const programDiagnosticsInFile = programDiagnostics.getDiagnostics(sourceFile.fileName);
diff --git a/src/services/codefixes/disableJsDiagnostics.ts b/src/services/codefixes/disableJsDiagnostics.ts
index c18c0153a03..621555cf84b 100644
--- a/src/services/codefixes/disableJsDiagnostics.ts
+++ b/src/services/codefixes/disableJsDiagnostics.ts
@@ -1,4 +1,4 @@
-/* @internal */
+/* @internal */
 namespace ts.codefix {
     registerCodeFix({
         errorCodes: getApplicableDiagnosticCodes(),
@@ -12,10 +12,6 @@ namespace ts.codefix {
             .map(d => allDiagnostcs[d].code);
     }
 
-    function shouldCheckJsFile(sourceFile: SourceFile, compilerOptions: CompilerOptions) {
-        return sourceFile.checkJsDirective ? sourceFile.checkJsDirective.enabled : compilerOptions.checkJs;
-    }
-
     function getSuppressCommentLocationForLocation(sourceFile: SourceFile, position: number, newLineCharacter: string) {
         let { line } = getLineAndCharacterOfPosition(sourceFile, position);
         const lineStartPosition = getStartPositionOfLine(line, sourceFile);
@@ -46,7 +42,7 @@ namespace ts.codefix {
     function getDisableJsDiagnosticsCodeActions(context: CodeFixContext): CodeAction[] | undefined {
         const { sourceFile, program, newLineCharacter, span } = context;
 
-        if (!isInJavaScriptFile(sourceFile) || !shouldCheckJsFile(sourceFile, program.getCompilerOptions())) {
+        if (!isInJavaScriptFile(sourceFile) || !isCheckJsEnabledForFile(sourceFile, program.getCompilerOptions())) {
             return undefined;
         }