diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index f44355a38..a0c38f5c0 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,6 @@
 August 2, 2009  (Changes by Graf Zahl)
+- Added A_Mushroom compatibility option for Dehacked.
+- Added Gez's submission for interhubamount DECORATE property.
 - Fixed: The big endian version of PalEntry did not add the DWORD d field.
 - Fixed: TObjPtr did not use a union to map its 2 pointers together.
 - Added a compatibility mode for A_Mushroom. For DECORATE it is an additional
diff --git a/src/compatibility.cpp b/src/compatibility.cpp
index ba817aaa6..8d9726d48 100644
--- a/src/compatibility.cpp
+++ b/src/compatibility.cpp
@@ -100,6 +100,7 @@ static FCompatOption Options[] =
 	{ "crossdropoff",			COMPATF_CROSSDROPOFF, 0 },
 	{ "wallrun",				COMPATF_WALLRUN, 0 },		// [GZ] Added for CC MAP29
 	{ "anybossdeath",			COMPATF_ANYBOSSDEATH, 0},	// [GZ] Added for UAC_DEAD
+	{ "mushroom",				COMPATF_MUSHROOM, 0},
 	{ NULL, 0, 0 }
 };
 
diff --git a/src/d_main.cpp b/src/d_main.cpp
index e4d6fb9a2..83141b0e0 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -466,7 +466,7 @@ CUSTOM_CVAR(Int, compatmode, 0, CVAR_ARCHIVE|CVAR_NOINITCALL)
 		break;
 
 	case 3:
-		v = COMPATF_TRACE|COMPATF_SOUNDTARGET|COMPATF_BOOMSCROLL;
+		v = COMPATF_TRACE|COMPATF_SOUNDTARGET|COMPATF_BOOMSCROLL|COMPATF_MUSHROOM;
 		break;
 
 	case 4:
@@ -499,6 +499,7 @@ CVAR (Flag, compat_missileclip,	compatflags, COMPATF_MISSILECLIP);
 CVAR (Flag, compat_crossdropoff,compatflags, COMPATF_CROSSDROPOFF);
 CVAR (Flag, compat_anybossdeath,compatflags, COMPATF_ANYBOSSDEATH);
 CVAR (Flag, compat_minotaur,	compatflags, COMPATF_MINOTAUR);
+CVAR (Flag, compat_mushroom,	compatflags, COMPATF_MUSHROOM);
 
 //==========================================================================
 //
diff --git a/src/doomdef.h b/src/doomdef.h
index 03a4fffd6..44cfb7a2a 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -317,6 +317,7 @@ enum
 	COMPATF_CROSSDROPOFF	= 1 << 20,	// monsters can't be pushed over dropoffs
 	COMPATF_ANYBOSSDEATH	= 1 << 21,	// [GZ] Any monster which calls BOSSDEATH counts for level specials
 	COMPATF_MINOTAUR		= 1 << 22,	// Minotaur's floor flame is exploded immediately when feet are clipped
+	COMPATF_MUSHROOM		= 1 << 23,	// Force original velocity calculations for A_Mushroom in Dehacked oods.
 };
 
 // Emulate old bugs for select maps. These are not exposed by a cvar
diff --git a/src/g_doom/a_fatso.cpp b/src/g_doom/a_fatso.cpp
index 66cd47aac..feb476377 100644
--- a/src/g_doom/a_fatso.cpp
+++ b/src/g_doom/a_fatso.cpp
@@ -149,7 +149,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_Mushroom)
 			target->x = self->x + (i << FRACBITS); // Aim in many directions from source
 			target->y = self->y + (j << FRACBITS);
 			target->z = self->z + (P_AproxDistance(i,j) << (FRACBITS+2)); // Aim up fairly high
-			if (flags == 0 && self->state->Misc1 == 0)
+			if (flags == 0 && (self->state->Misc1 == 0 || !(i_compatflags & COMPATF_MUSHROOM)))
 			{
 				mo = P_SpawnMissile (self, target, spawntype); // Launch fireball
 			}
diff --git a/src/g_game.cpp b/src/g_game.cpp
index 5de961ae1..47a93df71 100644
--- a/src/g_game.cpp
+++ b/src/g_game.cpp
@@ -1181,7 +1181,7 @@ void G_PlayerFinishLevel (int player, EFinishLevelType mode, bool resetinventory
 		while (item != NULL)
 		{
 			next = item->Inventory;
-			if (item->ItemFlags & IF_INTERHUBSTRIP)
+			if (item->InterHubAmount < 1)
 			{
 				item->Destroy ();
 			}
@@ -1190,14 +1190,13 @@ void G_PlayerFinishLevel (int player, EFinishLevelType mode, bool resetinventory
 	}
 
 	if (mode == FINISH_NoHub && !(level.flags2 & LEVEL2_KEEPFULLINVENTORY))
-	{ // Reduce all owned (visible) inventory to 1 item each
+	{ // Reduce all owned (visible) inventory to defined maximum interhub amount
 		for (item = p->mo->Inventory; item != NULL; item = item->Inventory)
 		{
-			// There may be depletable items with an amount of 0.
-			// Those need to stay at 0; the rest get dropped to 1.
-			if (item->ItemFlags & IF_INVBAR && item->Amount > 1)
+			// If the player is carrying more samples of an item than allowed, reduce amount accordingly
+			if (item->ItemFlags & IF_INVBAR && item->Amount > item->InterHubAmount)
 			{
-				item->Amount = 1;
+				item->Amount = item->InterHubAmount;
 			}
 		}
 	}
diff --git a/src/g_mapinfo.cpp b/src/g_mapinfo.cpp
index bb68e7d72..bd61d02ae 100644
--- a/src/g_mapinfo.cpp
+++ b/src/g_mapinfo.cpp
@@ -1340,6 +1340,7 @@ MapFlagHandlers[] =
 	{ "compat_crossdropoff",			MITYPE_COMPATFLAG, COMPATF_CROSSDROPOFF},
 	{ "compat_anybossdeath",			MITYPE_COMPATFLAG, COMPATF_ANYBOSSDEATH},
 	{ "compat_minotaur",				MITYPE_COMPATFLAG, COMPATF_MINOTAUR},
+	{ "compat_mushroom",				MITYPE_COMPATFLAG, COMPATF_MUSHROOM},
 	{ "cd_start_track",					MITYPE_EATNEXT,	0, 0 },
 	{ "cd_end1_track",					MITYPE_EATNEXT,	0, 0 },
 	{ "cd_end2_track",					MITYPE_EATNEXT,	0, 0 },
diff --git a/src/g_shared/a_pickups.h b/src/g_shared/a_pickups.h
index 78bb7ca59..f1a38afbb 100644
--- a/src/g_shared/a_pickups.h
+++ b/src/g_shared/a_pickups.h
@@ -119,7 +119,7 @@ enum
 	IF_UNDROPPABLE		= 1<<5,		// The player cannot manually drop the item
 	IF_INVBAR			= 1<<6,		// Item appears in the inventory bar
 	IF_HUBPOWER			= 1<<7,		// Powerup is kept when moving in a hub
-	IF_INTERHUBSTRIP	= 1<<8,		// Item is removed when travelling between hubs
+//	IF_INTERHUBSTRIP	= 1<<8,		// Item is removed when travelling between hubs
 	IF_ADDITIVETIME		= 1<<9,		// when picked up while another item is active, time is added instead of replaced.
 	IF_ALWAYSPICKUP		= 1<<10,	// For IF_AUTOACTIVATE, MaxAmount=0 items: Always "pick up", even if it doesn't do anything
 	IF_FANCYPICKUPSOUND	= 1<<11,	// Play pickup sound in "surround" mode
@@ -165,6 +165,7 @@ public:
 	TObjPtr<AActor> Owner;		// Who owns this item? NULL if it's still a pickup.
 	int Amount;					// Amount of item this instance has
 	int MaxAmount;				// Max amount of item this instance can have
+	int InterHubAmount;			// Amount of item that can be kept between hubs or levels
 	int RespawnTics;			// Tics from pickup time to respawn time
 	FTextureID Icon;			// Icon to show on status bar or HUD
 	int DropTime;				// Countdown after dropping
diff --git a/src/m_options.cpp b/src/m_options.cpp
index 543c10599..0241074c8 100644
--- a/src/m_options.cpp
+++ b/src/m_options.cpp
@@ -1104,6 +1104,7 @@ static menuitem_t CompatibilityItems[] = {
 	{ bitflag,  "Use Doom heights for missile clipping",	{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_MISSILECLIP} },
 	{ bitflag,  "Allow any bossdeath for level special",	{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_ANYBOSSDEATH} },
 	{ bitflag,  "No Minotaur floor flames in water",		{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_MINOTAUR} },
+	{ bitflag,  "Original A_Mushroom speed in DEH mods",	{&compatflags}, {0}, {0}, {0}, {(value_t *)COMPATF_MUSHROOM} },
 	
 	{ discrete, "Interpolate monster movement",	{&nomonsterinterpolation},		{2.0}, {0.0},	{0.0}, {NoYes} },
 };
diff --git a/src/thingdef/thingdef.h b/src/thingdef/thingdef.h
index 1d95bc92d..95ce02222 100644
--- a/src/thingdef/thingdef.h
+++ b/src/thingdef/thingdef.h
@@ -210,6 +210,7 @@ enum
 	DEPF_HERETICBOUNCE,
 	DEPF_HEXENBOUNCE,
 	DEPF_DOOMBOUNCE,
+	DEPF_INTERHUBSTRIP,
 };
 
 enum
diff --git a/src/thingdef/thingdef_data.cpp b/src/thingdef/thingdef_data.cpp
index a6f81923b..7e3d25780 100644
--- a/src/thingdef/thingdef_data.cpp
+++ b/src/thingdef/thingdef_data.cpp
@@ -253,7 +253,6 @@ static FFlagDef InventoryFlags[] =
 	DEFINE_FLAG(IF, UNDROPPABLE, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, INVBAR, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, HUBPOWER, AInventory, ItemFlags),
-	DEFINE_FLAG(IF, INTERHUBSTRIP, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, ALWAYSPICKUP, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, FANCYPICKUPSOUND, AInventory, ItemFlags),
 	DEFINE_FLAG(IF, BIGPOWERUP, AInventory, ItemFlags),
@@ -264,6 +263,7 @@ static FFlagDef InventoryFlags[] =
 	DEFINE_FLAG(IF, PERSISTENTPOWER, AInventory, ItemFlags),
 
 	DEFINE_DEPRECATED_FLAG(PICKUPFLASH),
+	DEFINE_DEPRECATED_FLAG(INTERHUBSTRIP),
 };
 
 static FFlagDef WeaponFlags[] =
diff --git a/src/thingdef/thingdef_properties.cpp b/src/thingdef/thingdef_properties.cpp
index a271e3890..5c73bb519 100644
--- a/src/thingdef/thingdef_properties.cpp
+++ b/src/thingdef/thingdef_properties.cpp
@@ -148,6 +148,8 @@ void HandleDeprecatedFlags(AActor *defaults, FActorInfo *info, bool set, int ind
 			static_cast<AInventory*>(defaults)->PickupFlash = NULL;
 		}
 		break;
+	case DEPF_INTERHUBSTRIP: // Old system was 0 or 1, so if the flag is cleared, assume 1.
+		static_cast<AInventory*>(defaults)->InterHubAmount = set ? 0 : 1;
 	default:
 		break;	// silence GCC
 	}
@@ -1220,6 +1222,15 @@ DEFINE_CLASS_PROPERTY(icon, S, Inventory)
 	}
 }
 
+//==========================================================================
+//
+//==========================================================================
+DEFINE_CLASS_PROPERTY(interhubamount, I, Inventory)
+{
+	PROP_INT_PARM(i, 0);
+	defaults->InterHubAmount = i;
+}
+
 //==========================================================================
 //
 //==========================================================================
diff --git a/wadsrc/static/actors/shared/inventory.txt b/wadsrc/static/actors/shared/inventory.txt
index 8850932ab..acda21f8f 100644
--- a/wadsrc/static/actors/shared/inventory.txt
+++ b/wadsrc/static/actors/shared/inventory.txt
@@ -2,6 +2,7 @@ ACTOR Inventory native
 {
 	Inventory.Amount 1
 	Inventory.MaxAmount 1
+	Inventory.InterHubAmount 1
 	Inventory.UseSound "misc/invuse"
 	Inventory.PickupSound "misc/i_pkup"