diff --git a/Source/objects.cpp b/Source/objects.cpp
index de180e75b..87ed1924b 100644
--- a/Source/objects.cpp
+++ b/Source/objects.cpp
@@ -426,7 +426,7 @@ void AddL3Objs(int x1, int y1, int x2, int y2)
 	}
 }
 
-BOOL WallTrapLocOk(int xp, int yp)
+DIABOOL WallTrapLocOk(int xp, int yp)
 {
 	if (dFlags[xp][yp] & BFLAG_POPULATED)
 		return FALSE;
diff --git a/Source/objects.h b/Source/objects.h
index a82ffae52..a4c391050 100644
--- a/Source/objects.h
+++ b/Source/objects.h
@@ -28,7 +28,7 @@ void InitRndBarrels();
 void AddL1Objs(int x1, int y1, int x2, int y2);
 void AddL2Objs(int x1, int y1, int x2, int y2);
 void AddL3Objs(int x1, int y1, int x2, int y2);
-BOOL WallTrapLocOk(int xp, int yp);
+DIABOOL WallTrapLocOk(int xp, int yp);
 void AddL2Torches();
 DIABOOL TorchLocOK(int xp, int yp);
 void AddObjTraps();