diff --git a/PC/winreg.c b/PC/winreg.c
index ae0c292b7172e9..28b316ae2f4cb9 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -521,7 +521,7 @@ fixupMultiSZ(wchar_t **str, wchar_t *data, int len)
     Q = data + len;
     for (P = data, i = 0; P < Q && *P != '\0'; P++, i++) {
         str[i] = P;
-        for(; *P != '\0'; P++)
+        for (; P < Q && *P != '\0'; P++)
             ;
     }
 }