diff --git a/lib/css/CssModulesPlugin.js b/lib/css/CssModulesPlugin.js
index 53202441c..fcc0a773f 100644
--- a/lib/css/CssModulesPlugin.js
+++ b/lib/css/CssModulesPlugin.js
@@ -368,10 +368,12 @@ class CssModulesPlugin {
 					if (module instanceof CssModule && module.hot) {
 						const exports = module.buildInfo.cssData.exports;
 						const stringifiedExports = JSON.stringify(
-							Array.from(exports).reduce((obj, [key, value]) => {
-								obj[key] = value;
-								return obj;
-							}, {})
+							JSON.stringify(
+								Array.from(exports).reduce((obj, [key, value]) => {
+									obj[key] = value;
+									return obj;
+								}, {})
+							)
 						);
 
 						const hmrCode = Template.asString([