diff --git a/src/p_enemy.c b/src/p_enemy.c
index 86f7af252..fe19456b7 100644
--- a/src/p_enemy.c
+++ b/src/p_enemy.c
@@ -330,7 +330,7 @@ static int P_IsUnderDamage(mobj_t *actor)
 static fixed_t xspeed[8] = {FRACUNIT,47000,0,-47000,-FRACUNIT,-47000,0,47000};
 static fixed_t yspeed[8] = {0,47000,FRACUNIT,47000,0,-47000,-FRACUNIT,-47000};
 
-static boolean P_Move(mobj_t *actor, boolean dropoff) // killough 9/12/98
+static boolean P_Move(mobj_t *actor, int dropoff) // killough 9/12/98
 {
   fixed_t tryx, tryy, deltax, deltay;
   boolean try_ok;
@@ -497,7 +497,7 @@ static boolean P_SmartMove(mobj_t *actor)
       P_Random(pr_dropoff) < 235)
     dropoff = 2;
 
-  if (!P_Move(actor, !!dropoff))
+  if (!P_Move(actor, dropoff))
     return false;
 
   // killough 9/9/98: avoid crushing ceilings or other damaging areas
diff --git a/src/p_map.c b/src/p_map.c
index e8a1640c2..c65de0ce1 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -843,7 +843,7 @@ boolean P_CheckPosition(mobj_t *thing, fixed_t x, fixed_t y)
 //
 // killough 3/15/98: allow dropoff as option
 
-boolean P_TryMove(mobj_t *thing, fixed_t x, fixed_t y, boolean dropoff)
+boolean P_TryMove(mobj_t *thing, fixed_t x, fixed_t y, int dropoff)
 {
   fixed_t oldx, oldy;
 
diff --git a/src/p_map.h b/src/p_map.h
index 531f295ab..ad241cc3b 100644
--- a/src/p_map.h
+++ b/src/p_map.h
@@ -44,7 +44,7 @@ struct sector_s;
 #define CROSSHAIR_AIM 1
 
 // killough 3/15/98: add fourth argument to P_TryMove
-boolean P_TryMove(struct mobj_s *thing, fixed_t x, fixed_t y, boolean dropoff);
+boolean P_TryMove(struct mobj_s *thing, fixed_t x, fixed_t y, int dropoff);
 
 // killough 8/9/98: extra argument for telefragging
 boolean P_TeleportMove(struct mobj_s *thing, fixed_t x, fixed_t y, boolean boss);