diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index 0058f53d4..ad7d36bf8 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,11 @@
 October 5, 2008  (Changes by Graf Zahl)
+- Finally has the right idea how to restore Doom's original clipping of projectiles
+  against decorations without breaking anything newer:
+  Added a new 'projectilepassheight' property that defines an alternative height
+  that is only used when checking a projectile's movement against this actor.
+  If the value is positive it is used regardless of other settings, if it is
+  negative, its absolute will be used if a new compatibility option is enabled
+  and if it is 0 the normal height will be used.
 - Fixed: Powerup.Color's handler contained an unnecessary 'else' which resulted
   in opaque powerup blends.
 
diff --git a/src/actor.h b/src/actor.h
index 0dfa13b7e..170235f38 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -650,6 +650,7 @@ public:
 	struct sector_t	*ceilingsector;
 	FTextureID		ceilingpic;			// contacted sec ceilingpic
 	fixed_t			radius, height;		// for movement checking
+	fixed_t			projectilepassheight;	// height for clipping projectile movement against this actor
 	fixed_t			momx, momy, momz;	// momentums
 	SDWORD			tics;				// state tic counter
 	FState			*state;
diff --git a/src/d_dehacked.cpp b/src/d_dehacked.cpp
index 5f32dc31f..0de22dcf2 100644
--- a/src/d_dehacked.cpp
+++ b/src/d_dehacked.cpp
@@ -746,6 +746,7 @@ static int PatchThing (int thingy)
 		else if (linelen == 6 && stricmp (Line1, "Height") == 0)
 		{
 			info->height = val;
+			info->projectilepassheight = 0;	// needs to be disabled
 			hadHeight = true;
 		}
 		else if (linelen == 14 && stricmp (Line1, "Missile damage") == 0)
@@ -1009,6 +1010,7 @@ static int PatchThing (int thingy)
 			thingy <= NumOrgHeights && thingy > 0)
 		{
 			info->height = OrgHeights[thingy - 1] * FRACUNIT;
+			info->projectilepassheight = 0;
 		}
 		// If the thing's shadow changed, change its fuzziness if not already specified
 		if ((info->flags ^ oldflags) & MF_SHADOW)
diff --git a/src/d_main.cpp b/src/d_main.cpp
index ce8aef512..7ee5f6e60 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -486,6 +486,7 @@ CVAR (Flag, compat_boomscroll,	compatflags, COMPATF_BOOMSCROLL);
 CVAR (Flag, compat_invisibility,compatflags, COMPATF_INVISIBILITY);
 CVAR (Flag, compat_silentinstantfloors,compatflags, COMPATF_SILENT_INSTANT_FLOORS);
 CVAR (Flag, compat_sectorsounds,compatflags, COMPATF_SECTORSOUNDS);
+CVAR (Flag, compat_missileclip,	compatflags, COMPATF_MISSILECLIP);
 
 //==========================================================================
 //
diff --git a/src/doomdef.h b/src/doomdef.h
index f43164710..036351931 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -273,6 +273,7 @@ enum
 	COMPATF_INVISIBILITY	= 1 << 16,	// Monsters can see semi-invisible players
 	COMPATF_SILENT_INSTANT_FLOORS = 1<<17,	// Instantly moving floors are not silent
 	COMPATF_SECTORSOUNDS	= 1 << 18,	// Sector sounds use original method for sound origin.
+	COMPATF_MISSILECLIP		= 1 << 19,	// Use original Doom heights for clipping against projectiles
 };
 
 // phares 3/20/98:
diff --git a/src/g_level.cpp b/src/g_level.cpp
index bfd6f13d5..7274e18f0 100644
--- a/src/g_level.cpp
+++ b/src/g_level.cpp
@@ -351,6 +351,7 @@ static const char *MapInfoMapLevel[] =
 	"compat_invisibility",
 	"compat_silent_instant_floors",
 	"compat_sectorsounds",
+	"compat_missileclip",
 	"bordertexture",
 	"f1", // [RC] F1 help
 	"noinfighting",
@@ -503,6 +504,7 @@ MapHandlers[] =
 	{ MITYPE_COMPATFLAG, COMPATF_INVISIBILITY},
 	{ MITYPE_COMPATFLAG, COMPATF_SILENT_INSTANT_FLOORS},
 	{ MITYPE_COMPATFLAG, COMPATF_SECTORSOUNDS},
+	{ MITYPE_COMPATFLAG, COMPATF_MISSILECLIP},
 	{ MITYPE_LUMPNAME,	lioffset(bordertexture), 0 },
 	{ MITYPE_LUMPNAME,  lioffset(f1), 0, }, 
 	{ MITYPE_SCFLAGS,	LEVEL_NOINFIGHTING, ~LEVEL_TOTALINFIGHTING },
diff --git a/src/m_options.cpp b/src/m_options.cpp
index 0e20c5f9d..e7bb69b4b 100644
--- a/src/m_options.cpp
+++ b/src/m_options.cpp
@@ -1103,6 +1103,7 @@ static menuitem_t CompatibilityItems[] = {
 	{ bitflag,	"Boom scrollers are additive",				{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_BOOMSCROLL} },
 	{ bitflag,	"Inst. moving floors are not silent",		{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_SILENT_INSTANT_FLOORS} },
 	{ bitflag,  "Sector sounds use center as source",		{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_SECTORSOUNDS} },
+	{ bitflag,  "Use Doom heights for missile clipping",	{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_MISSILECLIP} },
 	
 	{ discrete, "Interpolate monster movement",	{&nomonsterinterpolation},		{2.0}, {0.0},	{0.0}, {NoYes} },
 };
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 77ef763b1..da750cb6d 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -745,8 +745,24 @@ bool PIT_CheckThing (AActor *thing, FCheckPosition &tm)
 		{
 			return true;
 		}
+
+		int clipheight;
+		
+		if (thing->projectilepassheight > 0) 
+		{
+			clipheight = thing->projectilepassheight;
+		}
+		else if (thing->projectilepassheight < 0 && (i_compatflags & COMPATF_MISSILECLIP))
+		{
+			clipheight = -thing->projectilepassheight;
+		}
+		else
+		{
+			clipheight = thing->height;
+		}
+
 		// Check if it went over / under
-		if (tm.thing->z > thing->z + thing->height)
+		if (tm.thing->z > thing->z + clipheight)
 		{ // Over thing
 			return true;
 		}
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 39ab102fb..014763e75 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -220,6 +220,7 @@ void AActor::Serialize (FArchive &arc)
 		<< ceilingsector
 		<< radius
 		<< height
+		<< projectilepassheight
 		<< momx
 		<< momy
 		<< momz
diff --git a/src/thingdef/thingdef_properties.cpp b/src/thingdef/thingdef_properties.cpp
index 360f106ea..77a837be8 100644
--- a/src/thingdef/thingdef_properties.cpp
+++ b/src/thingdef/thingdef_properties.cpp
@@ -695,6 +695,15 @@ DEFINE_PROPERTY(height, F, Actor)
 	defaults->height=id;
 }
 
+//==========================================================================
+//
+//==========================================================================
+DEFINE_PROPERTY(projectilepassheight, F, Actor)
+{
+	PROP_FIXED_PARM(id, 0);
+	defaults->projectilepassheight=id;
+}
+
 //==========================================================================
 //
 //==========================================================================
diff --git a/src/version.h b/src/version.h
index ff6bff6a5..3a2d9d039 100644
--- a/src/version.h
+++ b/src/version.h
@@ -75,7 +75,7 @@
 // SAVESIG should match SAVEVER.
 
 // MINSAVEVER is the minimum level snapshot version that can be loaded.
-#define MINSAVEVER 1215
+#define MINSAVEVER 1253
 
 #if SVN_REVISION_NUMBER < MINSAVEVER
 // Never write a savegame with a version lower than what we need
diff --git a/wadsrc/static/actors/doom/doomdecorations.txt b/wadsrc/static/actors/doom/doomdecorations.txt
index 4dcdc885f..3d2073fed 100644
--- a/wadsrc/static/actors/doom/doomdecorations.txt
+++ b/wadsrc/static/actors/doom/doomdecorations.txt
@@ -6,6 +6,7 @@ ACTOR TechLamp 85
 	Game Doom
 	Radius 16
 	Height 80
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -22,6 +23,7 @@ ACTOR TechLamp2 86
 	Game Doom
 	Radius 16
 	Height 60
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -38,6 +40,7 @@ ACTOR Column 2028
 	Game Doom
 	Radius 16
 	Height 48
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -54,6 +57,7 @@ ACTOR TallGreenColumn 30
 	Game Doom
 	Radius 16
 	Height 52
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -70,6 +74,7 @@ ACTOR ShortGreenColumn 31
 	Game Doom
 	Radius 16
 	Height 40
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -86,6 +91,7 @@ ACTOR TallRedColumn 32
 	Game Doom
 	Radius 16
 	Height 52
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -102,6 +108,7 @@ ACTOR ShortRedColumn 33
 	Game Doom
 	Radius 16
 	Height 40
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -118,6 +125,7 @@ ACTOR SkullColumn 37
 	Game Doom
 	Radius 16
 	Height 40
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -134,6 +142,7 @@ ACTOR HeartColumn 36
 	Game Doom
 	Radius 16
 	Height 40
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -150,6 +159,7 @@ ACTOR EvilEye 41
 	Game Doom
 	Radius 16
 	Height 54
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -166,6 +176,7 @@ ACTOR FloatingSkull 42
 	Game Doom
 	Radius 16
 	Height 26
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -182,6 +193,7 @@ ACTOR TorchTree 43
 	Game Doom
 	Radius 16
 	Height 56
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -198,6 +210,7 @@ ACTOR BlueTorch 44
 	Game Doom
 	Radius 16
 	Height 68
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -214,6 +227,7 @@ ACTOR GreenTorch 45
 	Game Doom
 	Radius 16
 	Height 68
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -230,6 +244,7 @@ ACTOR RedTorch 46
 	Game Doom
 	Radius 16
 	Height 68
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -246,6 +261,7 @@ ACTOR ShortBlueTorch 55
 	Game Doom
 	Radius 16
 	Height 37
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -262,6 +278,7 @@ ACTOR ShortGreenTorch 56
 	Game Doom
 	Radius 16
 	Height 37
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -278,6 +295,7 @@ ACTOR ShortRedTorch 57
 	Game Doom
 	Radius 16
 	Height 37
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -294,6 +312,7 @@ ACTOR Stalagtite 47
 	Game Doom
 	Radius 16
 	Height 40
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -310,6 +329,7 @@ ACTOR TechPillar 48
 	Game Doom
 	Radius 16
 	Height 128
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -326,6 +346,7 @@ ACTOR Candlestick 34
 	Game Doom
 	Radius 20
 	Height 14
+	ProjectilePassHeight -16
 	States
 	{
 	Spawn:
@@ -341,6 +362,7 @@ ACTOR Candelabra 35
 	Game Doom
 	Radius 16
 	Height 60
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -489,6 +511,7 @@ ACTOR HeadOnAStick 27
 	Game Doom
 	Radius 16
 	Height 56
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -505,6 +528,7 @@ ACTOR HeadsOnAStick 28
 	Game Doom
 	Radius 16
 	Height 64
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -521,6 +545,7 @@ ACTOR HeadCandles 29
 	Game Doom
 	Radius 16
 	Height 42
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -537,6 +562,7 @@ ACTOR DeadStick 25
 	Game Doom
 	Radius 16
 	Height 64
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -553,6 +579,7 @@ ACTOR LiveStick 26
 	Game Doom
 	Radius 16
 	Height 64
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -570,6 +597,7 @@ ACTOR BigTree 54
 	Game Doom
 	Radius 32
 	Height 108
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
@@ -587,6 +615,7 @@ ACTOR BurningBarrel 70
 	SpawnID 149
 	Radius 16
 	Height 32
+	ProjectilePassHeight -16
 	+SOLID
 	States
 	{
diff --git a/zdoom.vcproj b/zdoom.vcproj
index a8d235bc9..d101c531e 100644
--- a/zdoom.vcproj
+++ b/zdoom.vcproj
@@ -1063,6 +1063,14 @@
 					RelativePath=".\src\thingdef\thingdef_exp.cpp"
 					>
 				</File>
+				<File
+					RelativePath=".\src\thingdef\thingdef_exp.h"
+					>
+				</File>
+				<File
+					RelativePath=".\src\thingdef\thingdef_exp_execute.cpp"
+					>
+				</File>
 				<File
 					RelativePath=".\src\thingdef\thingdef_main.cpp"
 					>