diff --git a/Source/objects.cpp b/Source/objects.cpp
index f9cc69ec3..dea941f0e 100644
--- a/Source/objects.cpp
+++ b/Source/objects.cpp
@@ -2591,7 +2591,7 @@ void OperateL1LDoor(int pnum, int oi, DIABOOL sendflag)
 	}
 }
 
-void OperateL2RDoor(int pnum, int oi, BOOL sendflag)
+void OperateL2RDoor(int pnum, int oi, DIABOOL sendflag)
 {
 	int xp, yp;
 
@@ -2673,7 +2673,7 @@ void OperateL2LDoor(int pnum, int oi, BOOL sendflag)
 	}
 }
 
-void OperateL3RDoor(int pnum, int oi, BOOL sendflag)
+void OperateL3RDoor(int pnum, int oi, DIABOOL sendflag)
 {
 	int xp, yp;
 
@@ -2715,7 +2715,7 @@ void OperateL3RDoor(int pnum, int oi, BOOL sendflag)
 	}
 }
 
-void OperateL3LDoor(int pnum, int oi, BOOL sendflag)
+void OperateL3LDoor(int pnum, int oi, DIABOOL sendflag)
 {
 	int xp, yp;