diff --git a/doc/fixes34.1 b/doc/fixes34.1
index be8233145..07a8110d2 100644
--- a/doc/fixes34.1
+++ b/doc/fixes34.1
@@ -53,6 +53,7 @@ avoid temporary disappearing Burdened message due to updating status line
 don't credit player's wisdom when makelevel creates random Elbereth engravings
 reduce insect/monster creation from monster spells
 avoid "couldn't place lregion type 5" warning when arriving at Plane of Fire
+avoid crash due to delayed poly or were change no longer being valid
 
 
 Platform- and/or Interface-Specific Fixes
diff --git a/src/allmain.c b/src/allmain.c
index 13c71c6d9..63e1c42b5 100644
--- a/src/allmain.c
+++ b/src/allmain.c
@@ -233,6 +233,10 @@ moveloop()
 			    }
 #endif
 			}
+			/* delayed change may not be valid anymore */
+			if ((change == 1 && !Polymorph) ||
+			    (change == 2 && u.ulycn == NON_PM))
+			    change = 0;
 			if(Polymorph && !rn2(100))
 			    change = 1;
 			else if (u.ulycn >= LOW_PM && !rn2(80 - (20 * night())))