diff --git a/src/maploader/compatibility.cpp b/src/maploader/compatibility.cpp
index 44dad087f..a3c979226 100644
--- a/src/maploader/compatibility.cpp
+++ b/src/maploader/compatibility.cpp
@@ -411,6 +411,27 @@ DEFINE_ACTION_FUNCTION(DLevelCompatibility, AddSectorTag)
 	return 0;
 }
 
+DEFINE_ACTION_FUNCTION(DLevelCompatibility, ClearLineIDs)
+{
+	PARAM_SELF_PROLOGUE(DLevelCompatibility);
+	PARAM_INT(line);
+	self->Level->tagManager.RemoveLineIDs(line);
+	return 0;
+}
+
+DEFINE_ACTION_FUNCTION(DLevelCompatibility, AddLineID)
+{
+	PARAM_SELF_PROLOGUE(DLevelCompatibility);
+	PARAM_INT(line);
+	PARAM_INT(tag);
+	
+	if ((unsigned)line < self->Level->lines.Size())
+	{
+		self->Level->tagManager.AddLineID(line, tag);
+	}
+	return 0;
+}
+
 DEFINE_ACTION_FUNCTION(DLevelCompatibility, SetThingSkills)
 {
 	PARAM_SELF_PROLOGUE(DLevelCompatibility);
diff --git a/src/p_tags.cpp b/src/p_tags.cpp
index d6f509f84..654f0bb40 100644
--- a/src/p_tags.cpp
+++ b/src/p_tags.cpp
@@ -104,6 +104,28 @@ void FTagManager::RemoveSectorTags(int sect)
 //
 //-----------------------------------------------------------------------------
 
+void FTagManager::RemoveLineIDs(int line)
+{
+	if (startForLine.Size() > (unsigned int)line)
+	{
+		int start = startForLine[line];
+		if (start >= 0)
+		{
+			while (allIDs[start].target == line)
+			{
+				allTags[start].tag = allTags[start].target = -1;
+				start++;
+			}
+		}
+	}
+}
+
+//-----------------------------------------------------------------------------
+//
+//
+//
+//-----------------------------------------------------------------------------
+
 void FTagManager::AddLineID(int line, int tag)
 {
 	if (tag == -1) return;	// For line IDs -1 means 'not set', unlike sectors.
diff --git a/src/p_tags.h b/src/p_tags.h
index 23b77ee8d..8ce6b3568 100644
--- a/src/p_tags.h
+++ b/src/p_tags.h
@@ -66,6 +66,7 @@ public:
 	void AddSectorTag(int sector, int tag);
 	void AddLineID(int line, int tag);
 	void RemoveSectorTags(int sect);
+	void RemoveLineIDs(int line);
 
 	void DumpTags();
 };
diff --git a/wadsrc/static/zscript/level_compatibility.txt b/wadsrc/static/zscript/level_compatibility.txt
index fe9ecf0a9..29378b01e 100644
--- a/wadsrc/static/zscript/level_compatibility.txt
+++ b/wadsrc/static/zscript/level_compatibility.txt
@@ -1185,6 +1185,8 @@ class LevelCompatibility native play
 
 	protected native void ClearSectorTags(int sector);
 	protected native void AddSectorTag(int sector, int tag);
+	protected native void ClearLineIDs(int line);
+	protected native void AddLineID(int line, int tag);
 	protected native void OffsetSectorPlane(int sector, int plane, double offset);
 	protected native void SetThingSkills(int thing, int skills);
 	protected native void SetThingXY(int thing, double x, double y);