diff --git a/calculator.asm b/calculator.asm
index 0f7986d..009c939 100644
--- a/calculator.asm
+++ b/calculator.asm
@@ -91,6 +91,8 @@ tmpWordLow: data 0
 
 ; out:
 ;  r0:r1 = word
+; trashes:
+;  r2, r3
 peekWord:
 	cleq r0, r0, popWord
 	cleq r0, r0, tmpStoreWord01