diff --git a/src/p_saveg.c b/src/p_saveg.c
index 4084d8c13..f2e8dcdb7 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -664,6 +664,7 @@ static void P_NetArchiveWorld(void)
 			diff2 |= SD_TAG;
 		if (ss->nexttag != ss->spawn_nexttag || ss->firsttag != ss->spawn_firsttag)
 			diff3 |= SD_TAGLIST;
+
 		if (ss->extra_colormap != ss->spawn_extra_colormap)
 			diff3 |= SD_COLORMAP;
 
@@ -729,6 +730,8 @@ static void P_NetArchiveWorld(void)
 				WRITEINT32(put, ss->firsttag);
 				WRITEINT32(put, ss->nexttag);
 			}
+			if (diff3 & SD_MIDMAP)
+				WRITEINT32(put, ss->midmap);
 
 			if (diff3 & SD_COLORMAP)
 				SaveExtraColormap(put, ss->extra_colormap);
diff --git a/src/p_setup.c b/src/p_setup.c
index c08c2ac58..5d7fd3179 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -1466,6 +1466,7 @@ static void P_LoadRawSideDefs2(void *data)
 		{
 			case 63: // variable colormap via 242 linedef
 			case 606: //SoM: 4/4/2000: Just colormap transfer
+			case 447: // Change colormap of tagged sectors! -- Monster Iestyn 14/06/18
 				// SoM: R_CreateColormap will only create a colormap in software mode...
 				// Perhaps we should just call it instead of doing the calculations here.
 				sec->extra_colormap = sec->spawn_extra_colormap = R_CreateColormap(msd->toptexture, msd->midtexture,
diff --git a/src/p_spec.c b/src/p_spec.c
index 5135676ab..b5e862749 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -3250,6 +3250,15 @@ static void P_ProcessLineSpecial(line_t *line, mobj_t *mo, sector_t *callsec)
 			}
 			break;
 
+		case 447: // Change colormap of tagged sectors!
+			// Basically this special applies a colormap to the tagged sectors, just like 606 (the colormap linedef)
+			// Except it is activated by linedef executor, not level load
+			// This could even override existing colormaps I believe
+			// -- Monster Iestyn 14/06/18
+			for (secnum = -1; (secnum = P_FindSectorFromLineTag(line, secnum)) >= 0 ;)
+				sectors[secnum].midmap = line->frontsector->midmap;
+			break;
+
 		case 448: // Change skybox viewpoint/centerpoint
 			if ((mo && mo->player && P_IsLocalPlayer(mo->player)) || (line->flags & ML_NOCLIMB))
 			{
diff --git a/src/r_defs.h b/src/r_defs.h
index 63ca29aa1..1d1d471e5 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -390,6 +390,7 @@ typedef struct sector_s
 
 	// these are saved for netgames, so do not let Lua touch these!
 	INT32 spawn_nexttag, spawn_firsttag; // the actual nexttag/firsttag values may differ if the sector's tag was changed
+	INT32 spawn_bottommap, spawn_midmap, spawn_topmap;
 
 	// offsets sector spawned with (via linedef type 7)
 	fixed_t spawn_flr_xoffs, spawn_flr_yoffs;