diff --git a/src/aof.c b/src/aof.c
index 1c1884b3d..50abe1d34 100644
--- a/src/aof.c
+++ b/src/aof.c
@@ -363,7 +363,7 @@ void flushAppendOnlyFile(int force) {
     /* We performed the write so reset the postponed flush sentinel to zero. */
     server.aof_flush_postponed_start = 0;
 
-    if (nwritten != (signed)sdslen(server.aof_buf)) {
+    if (nwritten != (ssize_t)sdslen(server.aof_buf)) {
         static time_t last_write_error_log = 0;
         int can_log = 0;