diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 261d47ea3..dfabd6420 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -142,6 +142,8 @@ int 			numgamesubsectors;
 bool			hasglnodes;
 
 TArray<FMapThing> MapThingsConverted;
+TMap<unsigned,unsigned>  MapThingsUserDataIndex;	// from mapthing idx -> user data idx
+TArray<FMapThingUserData> MapThingsUserData;
 
 int sidecount;
 sidei_t *sidetemp;
@@ -1637,7 +1639,7 @@ void P_LoadNodes (MapData * map)
 //===========================================================================
 CVAR(Bool, dumpspawnedthings, false, 0)
 
-void SpawnMapThing(int index, FMapThing *mt, int position)
+AActor *SpawnMapThing(int index, FMapThing *mt, int position)
 {
 	AActor *spawned = P_SpawnMapThing(mt, position);
 	if (dumpspawnedthings)
@@ -1647,6 +1649,42 @@ void SpawnMapThing(int index, FMapThing *mt, int position)
 			spawned? spawned->GetClass()->TypeName.GetChars() : "(none)");
 	}
 	T_AddSpawnedThing(spawned);
+	return spawned;
+}
+
+//===========================================================================
+//
+// SetMapThingUserData
+//
+//===========================================================================
+
+static void SetMapThingUserData(AActor *actor, unsigned udi)
+{
+	if (actor == NULL)
+	{
+		return;
+	}
+	while (MapThingsUserData[udi].Property != NAME_None)
+	{
+		FName varname = MapThingsUserData[udi].Property;
+		int value = MapThingsUserData[udi].Value;
+		PSymbol *sym = actor->GetClass()->Symbols.FindSymbol(varname, true);
+		PSymbolVariable *var;
+
+		udi++;
+
+		if (sym == NULL || sym->SymbolType != SYM_Variable ||
+			!(var = static_cast<PSymbolVariable *>(sym))->bUserVar ||
+			var->ValueType.Type != VAL_Int)
+		{
+			DPrintf("%s is not a user variable in class %s\n", varname.GetChars(),
+				actor->GetClass()->TypeName.GetChars());
+		}
+		else
+		{ // Set the value of the specified user variable.
+			*(int *)(reinterpret_cast<BYTE *>(actor) + var->offset) = value;
+		}
+	}
 }
 
 //===========================================================================
@@ -1685,7 +1723,7 @@ void P_LoadThings (MapData * map)
 	for (int i=0 ; i < numthings; i++, mt++)
 	{
 		// [RH] At this point, monsters unique to Doom II were weeded out
-		//		if the IWAD wasn't for Doom II. R_SpawnMapThing() can now
+		//		if the IWAD wasn't for Doom II. P_SpawnMapThing() can now
 		//		handle these and more cases better, so we just pass it
 		//		everything and let it decide what to do with them.
 
@@ -1780,7 +1818,12 @@ void P_SpawnThings (int position)
 
 	for (int i=0; i < numthings; i++)
 	{
-		SpawnMapThing (i, &MapThingsConverted[i], position);
+		AActor *actor = SpawnMapThing (i, &MapThingsConverted[i], position);
+		unsigned *udi = MapThingsUserDataIndex.CheckKey((unsigned)i);
+		if (udi != NULL)
+		{
+			SetMapThingUserData(actor, *udi);
+		}
 	}
 	for(int i=0; i<MAXPLAYERS; i++)
 	{
@@ -3501,6 +3544,8 @@ void P_SetupLevel (char *lumpname, int position)
 	wminfo.partime = 180;
 
 	MapThingsConverted.Clear();
+	MapThingsUserDataIndex.Clear();
+	MapThingsUserData.Clear();
 	linemap.Clear();
 	FCanvasTextureInfo::EmptyList ();
 	R_FreePastViewers ();
@@ -4071,6 +4116,8 @@ void P_SetupLevel (char *lumpname, int position)
 		}
 	}
 	MapThingsConverted.Clear();
+	MapThingsUserDataIndex.Clear();
+	MapThingsUserData.Clear();
 
 	if (glsegextras != NULL)
 	{
diff --git a/src/p_setup.h b/src/p_setup.h
index 61cda54fe..6e0a90a1d 100644
--- a/src/p_setup.h
+++ b/src/p_setup.h
@@ -159,4 +159,14 @@ struct FMissingCount
 };
 typedef TMap<FString,FMissingCount> FMissingTextureTracker;
 
+// Record of user data for UDMF maps
+struct FMapThingUserData
+{
+	FName Property;
+	int Value;
+};
+extern TMap<unsigned,unsigned> MapThingsUserDataIndex;	// from mapthing idx -> user data idx
+extern TArray<FMapThingUserData> MapThingsUserData;
+
+
 #endif
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index e087834b1..6a38708ea 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -627,9 +627,12 @@ public:
 				break;
 
 			default:
-				if (!strnicmp("user_", key.GetChars(), 5))
-				{
-					// Custom user key - handle later
+				if (0 == strnicmp("user_", key.GetChars(), 5))
+				{ // Custom user key - Sets an actor's user variable directly
+					FMapThingUserData ud;
+					ud.Property = key;
+					ud.Value = CheckInt(key);
+					MapThingsUserData.Push(ud);
 				}
 				break;
 			}
@@ -1603,8 +1606,18 @@ public:
 			if (sc.Compare("thing"))
 			{
 				FMapThing th;
+				unsigned userdatastart = MapThingsUserData.Size();
 				ParseThing(&th);
 				MapThingsConverted.Push(th);
+				if (userdatastart < MapThingsUserData.Size())
+				{ // User data added
+					MapThingsUserDataIndex[MapThingsConverted.Size()-1] = userdatastart;
+					// Mark end of the user data for this map thing
+					FMapThingUserData ud;
+					ud.Property = NAME_None;
+					ud.Value = 0;
+					MapThingsUserData.Push(ud);
+				}
 			}
 			else if (sc.Compare("linedef"))
 			{