diff --git a/WiFiManager.cpp b/WiFiManager.cpp
index c36f46d8..365d3407 100644
--- a/WiFiManager.cpp
+++ b/WiFiManager.cpp
@@ -3365,7 +3365,7 @@ void WiFiManager::DEBUG_WM(wm_debuglevel_t level,Generic text,Genericb textb) {
     uint32_t free = info.total_free_bytes;
     uint16_t max  = info.largest_free_block;
     uint8_t frag = 100 - (max * 100) / free;
-    _debugPort.printf("[MEM] free: %5lu | max: %5u | frag: %3u%% \n", free, max, frag);
+    _debugPort.printf("[MEM] free: %5u | max: %5u | frag: %3u%% \n", free, max, frag);
     #endif
   }