diff --git a/lib/css/CssModulesPlugin.js b/lib/css/CssModulesPlugin.js
index ec05301cf..a9c205c98 100644
--- a/lib/css/CssModulesPlugin.js
+++ b/lib/css/CssModulesPlugin.js
@@ -434,7 +434,7 @@ class CssModulesPlugin {
 				}
 				const exports =
 					codeGenResult.data && codeGenResult.data.get("css-exports");
-				const moduleId = chunkGraph.getModuleId(module) + "";
+				const moduleId = chunkGraph.getModuleId(module).replace(/\\/, "/") + "";
 				metaData.push(
 					`${
 						exports
@@ -456,6 +456,7 @@ class CssModulesPlugin {
 				throw e;
 			}
 		}
+		console.log(chunk.id);
 		source.add(
 			`head{--webpack-${escapeCss(
 				(uniqueName ? uniqueName + "-" : "") + chunk.id,