diff --git a/dom/base/DOMException.cpp b/dom/base/DOMException.cpp
index cedb9028c628..d84d198dfde7 100644
--- a/dom/base/DOMException.cpp
+++ b/dom/base/DOMException.cpp
@@ -692,6 +692,7 @@ DOMException::Constructor(GlobalObject& /* unused */,
       if (name.EqualsASCII(sDOMErrorMsgMap[idx].mName)) {
         exceptionResult = sDOMErrorMsgMap[idx].mNSResult;
         exceptionCode = sDOMErrorMsgMap[idx].mCode;
+        break;
       }
     }
   }