diff --git a/src/util/virutil.c b/src/util/virutil.c
index 91178d1515..2796671f4a 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -563,7 +563,7 @@ int virDiskNameParse(const char *name, int *disk, int *partition)
         }
     }
 
-    if (!ptr)
+    if (!ptr || !c_islower(*ptr))
         return -1;
 
     for (i = 0; *ptr; i++) {
diff --git a/tests/utiltest.c b/tests/utiltest.c
index 9b7a4a34f9..bd55d447b1 100644
--- a/tests/utiltest.c
+++ b/tests/utiltest.c
@@ -37,7 +37,8 @@ static struct testDiskName diskNamesPart[] = {
 };
 
 static const char* diskNamesInvalid[] = {
-    "sda00", "sda01", "sdb-1"
+    "sda00", "sda01", "sdb-1",
+    "vd2"
 };
 
 static int