diff --git a/lumber.asm b/lumber.asm
index 37d6d9c..d59b412 100644
--- a/lumber.asm
+++ b/lumber.asm
@@ -158,6 +158,9 @@ screen_level = gamescreen_middle+9*32+13
     pla
     tax
     ; fly birds
+    lda RTCLOK+2
+    and #%00000001
+    beq no_wings_change
     inc birdsHpos
     lda birdsHpos
     sta HPOSP0_u
diff --git a/lumber.xex b/lumber.xex
index 2a3388e..28983f4 100644
Binary files a/lumber.xex and b/lumber.xex differ