diff --git a/src/r_bsp.cpp b/src/r_bsp.cpp
index ddafbb014..87b880c27 100644
--- a/src/r_bsp.cpp
+++ b/src/r_bsp.cpp
@@ -246,26 +246,6 @@ void R_PortalClearClipSegs(INT32 start, INT32 end)
 	newend = solidsegs + 2;
 }
 
-// R_DoorClosed
-//
-// This function is used to fix the automap bug which
-// showed lines behind closed doors simply because the door had a dropoff.
-//
-// It assumes that Doom has already ruled out a door being closed because
-// of front-back closure (e.g. front floor is taller than back ceiling).
-static INT32 R_DoorClosed(void)
-{
-	return
-
-	// if door is closed because back is shut:
-	backsector->ceilingheight <= backsector->floorheight
-
-	// preserve a kind of transparent door/lift special effect:
-	&& (backsector->ceilingheight >= frontsector->ceilingheight || curline->sidedef->toptexture)
-
-	&& (backsector->floorheight <= frontsector->floorheight || curline->sidedef->bottomtexture);
-}
-
 //
 // If player's view height is underneath fake floor, lower the
 // drawn ceiling to be just under the floor height, and replace
@@ -625,7 +605,19 @@ static void R_AddLine(seg_t *line)
 			}
 
 			// Check for automap fix. Store in doorclosed for r_segs.c
-			doorclosed = R_DoorClosed();
+			//
+			// This is used to fix the automap bug which
+			// showed lines behind closed doors simply because the door had a dropoff.
+			//
+			// It assumes that Doom has already ruled out a door being closed because
+			// of front-back closure (e.g. front floor is taller than back ceiling).
+			//
+			// if door is closed because back is shut:
+			doorclosed = backsector->ceilingheight <= backsector->floorheight
+			// preserve a kind of transparent door/lift special effect:
+			&& (backsector->ceilingheight >= frontsector->ceilingheight || curline->sidedef->toptexture)
+			&& (backsector->floorheight <= frontsector->floorheight || curline->sidedef->bottomtexture);
+
 			if (doorclosed)
 				goto clipsolid;
 		}