diff --git a/constants.asm b/constants.asm
index bb030bcdc..5fc98c585 100644
--- a/constants.asm
+++ b/constants.asm
@@ -3653,6 +3653,12 @@ PREDEF_FILLMOVES EQU $1B
 PREDEF_GETUNOWNLETTER EQU $2D
 
 
+; flag manipulation
+RESET_FLAG EQU 0
+SET_FLAG   EQU 1
+CHECK_FLAG EQU 2
+
+
 ; script vars
 NUM_VARS EQU $1b
 VAR_MOVEMENT EQU $08