diff --git a/src/compatibility.cpp b/src/compatibility.cpp
index 7bc1c916cf..74b0354d8a 100644
--- a/src/compatibility.cpp
+++ b/src/compatibility.cpp
@@ -449,10 +449,11 @@ DEFINE_ACTION_FUNCTION(DLevelCompatibility, SetLineSectorRef)
 		&& lineidx < level.lines.Size()
 		&& sectoridx < level.sectors.Size())
 	{
-		if (side_t *side = level.lines[lineidx].sidedef[sideidx])
-		{
-			side->sector = &level.sectors[sectoridx];
-		}
+		line_t *line = &level.lines[lineidx];
+		side_t *side = line->sidedef[sideidx];
+		side->sector = &level.sectors[sectoridx];
+		if (sideidx == 0) line->frontsector = side->sector;
+		else line->backsector = side->sector;
 	}
 	ForceNodeBuild = true;
 	return 0;
@@ -505,3 +506,4 @@ CCMD (hiddencompatflags)
 {
 	Printf("%08x %08x %08x\n", ii_compatflags, ii_compatflags2, ib_compatflags);
 }
+
diff --git a/wadsrc/static/zscript/level_compatibility.txt b/wadsrc/static/zscript/level_compatibility.txt
index 32f85b72ca..773f10a229 100644
--- a/wadsrc/static/zscript/level_compatibility.txt
+++ b/wadsrc/static/zscript/level_compatibility.txt
@@ -571,7 +571,7 @@ class LevelCompatibility play
 				SetLineSectorRef(328, Line.front, 74);
 				SetLineSectorRef(329, Line.front, 74);
 				AddSectorTag(74, 4);
-				SetLineSpecial(357, Transfer_Heights, 4, 2);
+				SetLineSpecial(357, Transfer_Heights, 6);
 				break;
 			}
 			
@@ -589,6 +589,44 @@ class LevelCompatibility play
 				break;
 			}
 			
+			case '5A24FC83A3F9A2D6D54AF04E2E96684F': // AV.WAD MAP01
+			{
+				SetLineSectorRef(225, Line.back, 36);
+				SetLineSectorRef(222, Line.back, 36);
+				SetLineSectorRef(231, Line.back, 36);
+
+				SetLineSectorRef(223, Line.back, 36);
+				SetLineSectorRef(224, Line.back, 36);
+				SetLineSectorRef(227, Line.back, 36);
+
+				SetLineSectorRef(229, Line.back, 39);
+				SetLineSectorRef(233, Line.back, 39);
+
+				TextureID nukage = TexMan.CheckForTexture("NUKAGE1", TexMan.Type_Flat);
+				SetWallTexture(222, Line.front, Side.bottom, nukage);
+				SetWallTexture(223, Line.front, Side.bottom, nukage);
+				SetWallTexture(224, Line.front, Side.bottom, nukage);
+				SetWallTexture(225, Line.front, Side.bottom, nukage);
+				SetWallTexture(227, Line.front, Side.bottom, nukage);
+				SetWallTexture(231, Line.front, Side.bottom, nukage);
+				SetWallTexture(229, Line.front, Side.bottom, nukage);
+				SetWallTexture(233, Line.front, Side.bottom, nukage);
+
+				for(int i = 0; i < 8; i++)
+				{
+					SetLineSectorRef(i+234, Line.back, 37);
+					SetLineSectorRef(i+243, Line.back, 37);
+					SetWallTexture(i+234, Line.back, Side.bottom, nukage);
+					SetWallTexture(i+243, Line.back, Side.bottom, nukage);
+				}
+
+				SetLineSpecial(336, Transfer_Heights, 32000, 6);
+				AddSectorTag(40, 32000);
+				AddSectorTag(38, 32000);
+				AddSectorTag(37, 32000);
+				AddSectorTag(34, 32000);
+				break;
+			}
 		}
 	}