diff --git a/renovate.json b/renovate.json
index 8be80db..cebe9f8 100644
--- a/renovate.json
+++ b/renovate.json
@@ -14,7 +14,7 @@
         "^Makefile$"
       ],
       "matchStrings": [
-        "HELM_VERSION?=(?<currentValue>.*)"
+        "HELM_VERSION\\?=(?<currentValue>.*)"
       ],
       "datasourceTemplate": "github-releases",
       "depNameTemplate": "helm/helm",