diff --git a/src/basictypes.h b/src/basictypes.h
index ea56e9093..3159de428 100644
--- a/src/basictypes.h
+++ b/src/basictypes.h
@@ -112,6 +112,12 @@ struct fixedvec3
 		return *this;
 	}
 
+	operator fixedvec2()
+	{
+		fixedvec2 ret = { x, y };
+		return ret;
+	}
+
 };
 
 inline fixedvec2 operator +(const fixedvec2 &v1, const fixedvec2 &v2)
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 66c95d495..a7346fa17 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -462,8 +462,8 @@ bool P_TeleportMove(AActor *thing, fixed_t x, fixed_t y, fixed_t z, bool telefra
 		{
 			if (!(th->flags3 & thing->flags3 & MF3_DONTOVERLAP))
 			{
-				if (z > th->Top() ||	// overhead
-					z + thing->height < th->Z())	// underneath
+				if (z > cres.position.z + th->height ||	// overhead
+					z + thing->height < cres.position.z)	// underneath
 					continue;
 			}
 		}
@@ -557,9 +557,9 @@ void P_PlayerStartStomp(AActor *actor, bool mononly)
 		if (th->player != NULL && mononly)
 			continue;
 
-		if (actor->Z() > th->Top())
+		if (actor->Z() > cres.position.z + th->height)
 			continue;        // overhead
-		if (actor->Top() < th->Z())
+		if (actor->Top() < cres.position.z)
 			continue;        // underneath
 
 		P_DamageMobj(th, actor, actor, TELEFRAG_DAMAGE, NAME_Telefrag);
diff --git a/src/p_maputl.cpp b/src/p_maputl.cpp
index 59a7b9b54..722d1a6dd 100644
--- a/src/p_maputl.cpp
+++ b/src/p_maputl.cpp
@@ -534,6 +534,12 @@ void AActor::SetOrigin (fixed_t ix, fixed_t iy, fixed_t iz, bool moving)
 	P_FindFloorCeiling(this, FFCF_ONLYSPAWNPOS);
 }
 
+//===========================================================================
+//
+// FBlockNode - allows to link actors into multiple blocks in the blockmap
+//
+//===========================================================================
+
 FBlockNode *FBlockNode::FreeBlocks = NULL;
 
 FBlockNode *FBlockNode::Create (AActor *who, int x, int y, int group)
@@ -789,7 +795,9 @@ bool FMultiBlockLinesIterator::Next(FMultiBlockLinesIterator::CheckResult *item)
 	if (line != NULL)
 	{
 		item->line = line;
-		item->position = offset;
+		item->position.x = offset.x;
+		item->position.y = offset.y;
+		item->position.z = checkpoint.z;
 		item->portalflags = portalflags;
 		return true;
 	}
diff --git a/src/p_maputl.h b/src/p_maputl.h
index 2aacf3dd1..11260bcbf 100644
--- a/src/p_maputl.h
+++ b/src/p_maputl.h
@@ -220,7 +220,7 @@ public:
 	struct CheckResult
 	{
 		line_t *line;
-		fixedvec2 position;
+		fixedvec3 position;
 		int portalflags;
 	};