diff --git a/src/platforms/web/compiler/modules/class.js b/src/platforms/web/compiler/modules/class.js
index 81091675770..12a68c8b8cf 100644
--- a/src/platforms/web/compiler/modules/class.js
+++ b/src/platforms/web/compiler/modules/class.js
@@ -23,7 +23,7 @@ function transformNode (el: ASTElement, options: CompilerOptions) {
     }
   }
   if (staticClass) {
-    el.staticClass = JSON.stringify(staticClass.replace(/\s+/gi, " ").trim())
+    el.staticClass = JSON.stringify(staticClass.replace(/\s+/g, " ").trim())
   }
   const classBinding = getBindingAttr(el, 'class', false /* getStatic */)
   if (classBinding) {