diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index 9df8695b4f..62eefe2ec4 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,8 @@
-March 15, 2009  (Changes by Graf Zahl)
+March 16, 2009
+- Added support for loading ZGL2 nodes. (Only useful with UDMF and maps with
+  more than 65534 lines.)
+
+March 15, 2009  (Changes by Graf Zahl)
 - Fixed: AWeapon::PickupForAmmo accessed ammo type 1 when checking ammo type2.
 
 March 14, 2009
diff --git a/src/nodebuild.h b/src/nodebuild.h
index 4c7babbcca..1e0a2efaf7 100644
--- a/src/nodebuild.h
+++ b/src/nodebuild.h
@@ -219,7 +219,7 @@ private:
 	double AddIntersection (const node_t &node, int vertex);
 	void AddMinisegs (const node_t &node, DWORD splitseg, DWORD &fset, DWORD &rset);
 	DWORD CheckLoopStart (fixed_t dx, fixed_t dy, int vertex1, int vertex2);
-	DWORD CheckLoopEnd (fixed_t dx, fixed_t dy, int vertex1, int vertex2);
+	DWORD CheckLoopEnd (fixed_t dx, fixed_t dy, int vertex2);
 	void RemoveSegFromVert1 (DWORD segnum, int vertnum);
 	void RemoveSegFromVert2 (DWORD segnum, int vertnum);
 	DWORD AddMiniseg (int v1, int v2, DWORD partner, DWORD seg1, DWORD splitseg);
diff --git a/src/nodebuild_gl.cpp b/src/nodebuild_gl.cpp
index 475bccd213..e3453cd336 100644
--- a/src/nodebuild_gl.cpp
+++ b/src/nodebuild_gl.cpp
@@ -173,8 +173,8 @@ void FNodeBuilder::AddMinisegs (const node_t &node, DWORD splitseg, DWORD &fset,
 
 			if ((fseg1 = CheckLoopStart (node.dx, node.dy, prev->Info.Vertex, event->Info.Vertex)) != DWORD_MAX &&
 				(bseg1 = CheckLoopStart (-node.dx, -node.dy, event->Info.Vertex, prev->Info.Vertex)) != DWORD_MAX &&
-				(fseg2 = CheckLoopEnd (node.dx, node.dy, prev->Info.Vertex, event->Info.Vertex)) != DWORD_MAX &&
-				(bseg2 = CheckLoopEnd (-node.dx, -node.dy, event->Info.Vertex, prev->Info.Vertex)) != DWORD_MAX)
+				(fseg2 = CheckLoopEnd (node.dx, node.dy, event->Info.Vertex)) != DWORD_MAX &&
+				(bseg2 = CheckLoopEnd (-node.dx, -node.dy, prev->Info.Vertex)) != DWORD_MAX)
 			{
 				// Add miniseg on the front side
 				fnseg = AddMiniseg (prev->Info.Vertex, event->Info.Vertex, DWORD_MAX, fseg1, splitseg);
@@ -329,7 +329,7 @@ DWORD FNodeBuilder::CheckLoopStart (fixed_t dx, fixed_t dy, int vertex, int vert
 	return bestseg;
 }
 
-DWORD FNodeBuilder::CheckLoopEnd (fixed_t dx, fixed_t dy, int vertex1, int vertex)
+DWORD FNodeBuilder::CheckLoopEnd (fixed_t dx, fixed_t dy, int vertex)
 {
 	FPrivVert *v = &Vertices[vertex];
 	angle_t splitAngle = PointToAngle (dx, dy) + ANGLE_180;
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 857308e860..6a79c7bc74 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -749,7 +749,7 @@ void P_LoadZSegs (FileReaderZ &data)
 //
 //===========================================================================
 
-void P_LoadGLZSegs (FileReaderZ &data)
+void P_LoadGLZSegs (FileReaderZ &data, DWORD id)
 {
 	for (int i = 0; i < numsubsectors; ++i)
 	{
@@ -757,10 +757,21 @@ void P_LoadGLZSegs (FileReaderZ &data)
 		{
 			seg_t *seg;
 			DWORD v1, partner;
-			WORD line;
+			DWORD line;
+			WORD lineword;
 			BYTE side;
 
-			data >> v1 >> partner >> line >> side;
+			data >> v1 >> partner;
+			if (id == MAKE_ID('Z','G','L','2'))
+			{
+				data >> line;
+			}
+			else
+			{
+				data >> lineword;
+				line = lineword == 0xFFFF ? 0xFFFFFFFF : lineword;
+			}
+			data >> side;
 
 			seg = &segs[subsectors[i].firstline + j];
 			seg->v1 = &vertexes[v1];
@@ -780,7 +791,7 @@ void P_LoadGLZSegs (FileReaderZ &data)
 			{
 				seg->PartnerSeg = &segs[partner];
 			}
-			if (line != 0xFFFF)
+			if (line != 0xFFFFFFFF)
 			{
 				line_t *ldef;
 
@@ -891,7 +902,7 @@ static void P_LoadZNodes (FileReader &dalump, DWORD id)
 	}
 	else
 	{
-		P_LoadGLZSegs (data);
+		P_LoadGLZSegs (data, id);
 	}
 
 	// Read nodes
@@ -3455,7 +3466,7 @@ void P_SetupLevel (char *lumpname, int position)
 	{
 		// Check for compressed nodes first, then uncompressed nodes
 		FWadLump test;
-		DWORD id = MAKE_ID('X','x','X','x'), idcheck=0;
+		DWORD id = MAKE_ID('X','x','X','x'), idcheck = 0, idcheck2 = 0;
 
 		if (map->MapLumps[ML_ZNODES].Size != 0 && !UsingGLNodes)
 		{
@@ -3467,10 +3478,11 @@ void P_SetupLevel (char *lumpname, int position)
 			// If normal nodes are not present but GL nodes are, use them.
 			map->Seek(ML_GLZNODES);
 			idcheck = MAKE_ID('Z','G','L','N');
+			idcheck2 = MAKE_ID('Z','G','L','2');
 		}
 
 		map->file->Read (&id, 4);
-		if (id == idcheck)
+		if (id == idcheck || id == idcheck2)
 		{
 			try
 			{
@@ -3513,7 +3525,6 @@ void P_SetupLevel (char *lumpname, int position)
 			times[9].Unclock();
 		}
 		else ForceNodeBuild = true;
-
 	}
 	if (ForceNodeBuild)
 	{