diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index c5f9bc51e9..730dc304ad 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -1376,8 +1376,8 @@ bool AActor::FloorBounceMissile (secplane_t &plane)
 		if (abs(velz) < (fixed_t)(Mass * GetGravity() / 64))
 			velz = 0;
 	}
-	else if (BounceFlags & BOUNCE_AutoOff)
-	{
+	else if (plane.c > 0 && BounceFlags & BOUNCE_AutoOff)
+	{ // AutoOff only works when bouncing off a floor, not a ceiling.
 		if (!(flags & MF_NOGRAVITY) && (velz < 3*FRACUNIT))
 			BounceFlags &= ~BOUNCE_TypeMask;
 	}