diff --git a/wadsrc/static/zscript/level_compatibility.zs b/wadsrc/static/zscript/level_compatibility.zs
index 4ed450d9a4..b334d7f57b 100644
--- a/wadsrc/static/zscript/level_compatibility.zs
+++ b/wadsrc/static/zscript/level_compatibility.zs
@@ -898,6 +898,12 @@ class LevelCompatibility native play
 				break;
 			}
 
+			case 'D5FD90FA7A8133E7BFED682D3D313962': // strife1.wad map21
+			{
+				SetWallTexture(603, Line.front, Side.bottom, "IRON04");
+				break;
+			}
+
 			case 'DB31D71B11E3E4393B9C0CCB44A8639F': // rop_2015.wad e1m5
 			{
 				// Lower floor a bit so secret switch becomes accessible