diff --git a/src/util/virrandom.c b/src/util/virrandom.c
index 3c011a8615..7915f6531e 100644
--- a/src/util/virrandom.c
+++ b/src/util/virrandom.c
@@ -68,7 +68,9 @@ uint64_t virRandomBits(int nbits)
         return 0;
     }
 
-    ret &= (1ULL << nbits) - 1;
+    if (nbits < 64)
+        ret &= (1ULL << nbits) - 1;
+
     return ret;
 }