diff --git a/src/util/virutil.c b/src/util/virutil.c
index 170e921920efbf9f8ff2d5b2f15c6c938c704a6e..8bdcb02fd5d049e2ee98606e6d07a84d6f8b3115 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -562,7 +562,7 @@ int virDiskNameToIndex(const char *name)
 {
     int idx;
 
-    if (virDiskNameParse(name, &idx, NULL))
+    if (virDiskNameParse(name, &idx, NULL) < 0)
         idx = -1;
 
     return idx;