diff --git a/src/k_terrain.c b/src/k_terrain.c
index bc41bbc31..fa6f9742d 100644
--- a/src/k_terrain.c
+++ b/src/k_terrain.c
@@ -1630,7 +1630,7 @@ boolean K_TerrainHasAffect(terrain_t *terrain, boolean badonly)
 	|| terrain->trickPanel != 0
 	|| terrain->speedPad != 0
 	|| terrain->springStrength != 0
-	|| terrain->flags != 0);
+	|| (terrain->flags & (TRF_LIQUID|TRF_SNEAKERPANEL|TRF_TRIPWIRE)));
 }
 
 /*--------------------------------------------------