diff --git a/src/transports/smart.c b/src/transports/smart.c
index 11b4b09a4..7a35c39d8 100644
--- a/src/transports/smart.c
+++ b/src/transports/smart.c
@@ -444,7 +444,7 @@ static void git_smart__free(git_transport *transport)
 		git_pkt_free(p);
 
 	git_vector_free(refs);
-	git__free(t->proxy.url);
+	git__free((char *)t->proxy.url);
 
 	git_strarray_free(&t->custom_headers);