diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index c2c4c5111fd1f0cdcd911e61eaf691fd1c98f3e0..cab72c63cc9a30d5f51a1bc4ec9a37fadc05933b 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -141,7 +141,7 @@ virStorageBackendCopyToFD(virStorageVolDefPtr vol,
     size_t rbytes = READ_BLOCK_SIZE_DEFAULT;
     size_t wbytes = 0;
     int interval;
-    char *zerobuf;
+    char *zerobuf = NULL;
     char *buf = NULL;
     struct stat st;