diff --git a/block/curl.c b/block/curl.c
index 68cf83ce55..d7d93d967f 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -524,7 +524,7 @@ static int curl_init_state(BDRVCURLState *s, CURLState *state)
 #endif
 
 #ifdef DEBUG_VERBOSE
-        if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1)) {
+        if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1L)) {
             goto err;
         }
 #endif