diff --git a/dlls/msi/automation.c b/dlls/msi/automation.c
index 228d88744b2..01765cbe8ad 100644
--- a/dlls/msi/automation.c
+++ b/dlls/msi/automation.c
@@ -1366,7 +1366,7 @@ static HRESULT session_invoke(
 {
     SessionObject *session = (SessionObject*)This;
     WCHAR *szString;
-    DWORD dwLen;
+    DWORD dwLen = 0;
     MSIHANDLE msiHandle;
     LANGID langId;
     UINT ret;