diff --git a/block/curl.c b/block/curl.c
index 6a6cd72975..9516852971 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -759,6 +759,8 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
     // Get file size
 
     if (curl_init_state(s, state) < 0) {
+        pstrcpy(state->errmsg, CURL_ERROR_SIZE,
+                "curl library initialization failed.");
         goto out;
     }