diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index c06e95339f1..1c32d5dda4c 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -593,7 +593,8 @@ namespace FourSlash {
         public verifyNoErrors() {
             ts.forEachKey(this.inputFiles, fileName => {
                 if (!ts.isAnySupportedFileExtension(fileName)
-                    || !this.getProgram().getCompilerOptions().allowJs && !ts.extensionIsTS(ts.extensionFromPath(fileName))) return;
+                    || Harness.getConfigNameFromFileName(fileName)
+                    || !this.getProgram().getCompilerOptions().allowJs && !ts.resolutionExtensionIsTSOrJson(ts.extensionFromPath(fileName))) return;
                 const errors = this.getDiagnostics(fileName).filter(e => e.category !== ts.DiagnosticCategory.Suggestion);
                 if (errors.length) {
                     this.printErrorLog(/*expectErrors*/ false, errors);
diff --git a/tests/cases/fourslash/codeFixCannotFindModule_suggestion_falsePositive.ts b/tests/cases/fourslash/codeFixCannotFindModule_suggestion_falsePositive.ts
index 123d59d82a3..54afae7c4d1 100644
--- a/tests/cases/fourslash/codeFixCannotFindModule_suggestion_falsePositive.ts
+++ b/tests/cases/fourslash/codeFixCannotFindModule_suggestion_falsePositive.ts
@@ -5,7 +5,7 @@
 // @strict: true
 
 // @Filename: /node_modules/foo/bar.json
-////export const x = 0;
+////{ "a": 0 }
 
 // @Filename: /a.ts
 ////import abs = require([|"foo/bar.json"|]);