diff --git a/lib/log.h b/lib/log.h
index c30c53c5a7..be1d9fb592 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -91,7 +91,7 @@ extern void zlog_debug(const char *format, ...) PRINTF_ATTRIBUTE(1, 2);
 #define flog_err_sys(ferr_id, format, ...)                                     \
 	flog_err(ferr_id, format, ##__VA_ARGS__)
 #define flog_warn(ferr_id, format, ...)                                        \
-	zlog_warn("[EC %d] " format, ferr_id, ##__VA_ARGS__)
+	zlog_warn("[EC %"PRIu32"] " format, ferr_id, ##__VA_ARGS__)
 
 
 extern void zlog_thread_info(int log_level);