diff --git a/src/dsectoreffect.cpp b/src/dsectoreffect.cpp
index 6732a19dc..7bc9fc400 100644
--- a/src/dsectoreffect.cpp
+++ b/src/dsectoreffect.cpp
@@ -95,11 +95,11 @@ void DMover::Serialize (FArchive &arc)
 	arc << interpolation;
 }
 
-void DMover::StopInterpolation()
+void DMover::StopInterpolation(bool force)
 {
 	if (interpolation != NULL)
 	{
-		interpolation->DelRef();
+		interpolation->DelRef(force);
 		interpolation = NULL;
 	}
 }
diff --git a/src/dsectoreffect.h b/src/dsectoreffect.h
index 95e1178aa..3788c6d88 100644
--- a/src/dsectoreffect.h
+++ b/src/dsectoreffect.h
@@ -36,7 +36,7 @@ protected:
 	DMover ();
 	void Serialize (FArchive &arc);
 	void Destroy();
-	void StopInterpolation();
+	void StopInterpolation(bool force = false);
 	inline EResult MoveFloor (fixed_t speed, fixed_t dest, int crush, int direction, bool hexencrush)
 	{
 		return MovePlane (speed, dest, crush, 0, direction, hexencrush);
diff --git a/src/fragglescript/t_func.cpp b/src/fragglescript/t_func.cpp
index e5803fb3e..444750e03 100644
--- a/src/fragglescript/t_func.cpp
+++ b/src/fragglescript/t_func.cpp
@@ -1571,7 +1571,7 @@ public:
 		bool res = DMover::crushed != MoveFloor(speed, dest, crush, direction, false);
 		Destroy();
 		m_Sector->floordata=NULL;
-		StopInterpolation();
+		StopInterpolation(true);
 		m_Sector=NULL;
 		return res;
 	}
@@ -1656,6 +1656,14 @@ public:
 		m_Speed=movespeed;
 		m_Direction = _m_Direction;
 		m_FloorDestDist = moveheight;
+
+		// Do not interpolate instant movement floors.
+		fixed_t movedist = abs(-sec->floorplane.d - moveheight);
+		if (m_Speed >= movedist)
+		{
+			StopInterpolation(true);
+		}
+
 		StartFloorSound();
 	}
 };
@@ -1713,7 +1721,7 @@ public:
 		bool res = DMover::crushed != MoveCeiling(speed, dest, crush, direction, false);
 		Destroy();
 		m_Sector->ceilingdata=NULL;
-		StopInterpolation ();
+		StopInterpolation (true);
 		m_Sector=NULL;
 		return res;
 	}
@@ -1806,7 +1814,7 @@ public:
 		fixed_t movedist = abs(sec->ceilingplane.d - m_BottomHeight);
 		if (m_Speed >= movedist)
 		{
-			StopInterpolation ();
+			StopInterpolation (true);
 			m_Silent=2;
 		}
 		PlayCeilingSound();
diff --git a/src/p_ceiling.cpp b/src/p_ceiling.cpp
index 3203cf777..24ab121c4 100644
--- a/src/p_ceiling.cpp
+++ b/src/p_ceiling.cpp
@@ -412,7 +412,7 @@ DCeiling *DCeiling::Create(sector_t *sec, DCeiling::ECeiling type, line_t *line,
 	}
 	if (ceiling->m_Speed >= movedist)
 	{
-		ceiling->StopInterpolation();
+		ceiling->StopInterpolation(true);
 	}
 
 	// set texture/type change properties
diff --git a/src/p_floor.cpp b/src/p_floor.cpp
index 35e527383..c632e8ba2 100644
--- a/src/p_floor.cpp
+++ b/src/p_floor.cpp
@@ -478,7 +478,7 @@ bool EV_DoFloor (DFloor::EFloor floortype, line_t *line, int tag,
 			(floor->m_Direction<0 && floor->m_FloorDestDist<sec->floorplane.d) ||	// moving down but going up
 			(floor->m_Speed >= abs(sec->floorplane.d - floor->m_FloorDestDist)))	// moving in one step
 		{
-			floor->StopInterpolation();
+			floor->StopInterpolation(true);
 
 			// [Graf Zahl]
 			// Don't make sounds for instant movement hacks but make an exception for
diff --git a/src/r_data/r_interpolate.cpp b/src/r_data/r_interpolate.cpp
index 4ce3a3c7b..ed12cbf4e 100644
--- a/src/r_data/r_interpolate.cpp
+++ b/src/r_data/r_interpolate.cpp
@@ -344,9 +344,10 @@ int DInterpolation::AddRef()
 //
 //==========================================================================
 
-int DInterpolation::DelRef()
+int DInterpolation::DelRef(bool force)
 {
 	if (refcount > 0) --refcount;
+	if (force && refcount == 0) Destroy();
 	return refcount;
 }
 
@@ -943,20 +944,6 @@ DInterpolation *sector_t::SetInterpolation(int position, bool attach)
 //
 //==========================================================================
 
-void sector_t::StopInterpolation(int position)
-{
-	if (interpolations[position] != NULL)
-	{
-		interpolations[position]->DelRef();
-	}
-}
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
 DInterpolation *FPolyObj::SetInterpolation()
 {
 	if (interpolation != NULL)
diff --git a/src/r_data/r_interpolate.h b/src/r_data/r_interpolate.h
index 29e8a6171..92e74c3f2 100644
--- a/src/r_data/r_interpolate.h
+++ b/src/r_data/r_interpolate.h
@@ -25,7 +25,7 @@ protected:
 
 public:
 	int AddRef();
-	int DelRef();
+	int DelRef(bool force = false);
 
 	virtual void Destroy();
 	virtual void UpdateInterpolation() = 0;
diff --git a/src/r_defs.h b/src/r_defs.h
index fc9d522de..a9b09c9e6 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -504,7 +504,6 @@ struct sector_t
 	sector_t *GetHeightSec() const;
 
 	DInterpolation *SetInterpolation(int position, bool attach);
-	void StopInterpolation(int position);
 
 	ASkyViewpoint *GetSkyBox(int which);