diff --git a/ports/esp8266/ets_alt_task.c b/ports/esp8266/ets_alt_task.c
index 6f9ae67f21..b724b8f14a 100644
--- a/ports/esp8266/ets_alt_task.c
+++ b/ports/esp8266/ets_alt_task.c
@@ -166,6 +166,11 @@ bool ets_loop_iter(void) {
         }
         ets_intr_unlock();
     }
+
+    if (!progress && idle_cb) {
+        idle_cb(idle_arg);
+    }
+
     return progress;
 }