diff --git a/source/games/sw/src/cache.cpp b/source/games/sw/src/cache.cpp
index e1340f3d6..4251d7425 100644
--- a/source/games/sw/src/cache.cpp
+++ b/source/games/sw/src/cache.cpp
@@ -64,9 +64,7 @@ void PreCacheOverride(void)
 	SWStatIterator it(STAT_CEILING_FLOOR_PIC_OVERRIDE);
 	while (auto actor = it.Next())
 	{
-		int j = SP_TAG2(actor); // picnum
-		if(j >= 0 && j <= MAXTILES)
-			markTextureForPrecache(tileGetTextureID(j), 0);
+		markTextureForPrecache(actor->texparam, 0);
 	}
 }
 
diff --git a/source/games/sw/src/draw.cpp b/source/games/sw/src/draw.cpp
index 377eadf87..141d401ce 100644
--- a/source/games/sw/src/draw.cpp
+++ b/source/games/sw/src/draw.cpp
@@ -1171,7 +1171,8 @@ void UpdateWallPortalState()
     {
         if (SP_TAG3(actor) == 0)
         {
-            // back up ceilingpicnum and ceilingstat
+            // back up ceilingpic and ceilingstat
+            // std::swap(actor->sector->ceilingtexture, actor->texparam);
             SP_TAG5(actor) = actor->sector()->ceilingpicnum;
             actor->sector()->ceilingpicnum = SP_TAG2(actor);
             SP_TAG4(actor) = actor->sector()->ceilingstat;
@@ -1180,6 +1181,7 @@ void UpdateWallPortalState()
         }
         else if (SP_TAG3(actor) == 1)
         {
+            // std::swap(actor->sector->floortexture, actor->texparam);
             SP_TAG5(actor) = actor->sector()->floorpicnum;
             actor->sector()->floorpicnum = SP_TAG2(actor);
             SP_TAG4(actor) = actor->sector()->floorstat;
@@ -1203,13 +1205,15 @@ void RestorePortalState()
     {
         if (SP_TAG3(actor) == 0)
         {
-            // restore ceilingpicnum and ceilingstat
+            // restore ceilingpic and ceilingstat
+            // std::swap(actor->sector->ceilingtexture, actor->texparam);
             actor->sector()->ceilingpicnum = SP_TAG5(actor);
             actor->sector()->ceilingstat = ESectorFlags::FromInt(SP_TAG4(actor));
             actor->sector()->ceilingstat &= ~(CSTAT_SECTOR_SKY);
         }
         else if (SP_TAG3(actor) == 1)
         {
+            // std::swap(actor->sector->floortexture, actor->texparam);
             actor->sector()->floorpicnum = SP_TAG5(actor);
             actor->sector()->floorstat = ESectorFlags::FromInt(SP_TAG4(actor));
             actor->sector()->floorstat &= ~(CSTAT_SECTOR_SKY);
diff --git a/source/games/sw/src/jsector.cpp b/source/games/sw/src/jsector.cpp
index 7778e556e..9f1856244 100644
--- a/source/games/sw/src/jsector.cpp
+++ b/source/games/sw/src/jsector.cpp
@@ -279,7 +279,7 @@ void JS_InitMirrors(void)
                 if (mirrorcnt >= MAXMIRRORS)
                 {
                     Printf("MAXMIRRORS reached! Skipping mirror wall\n");
-                    wal.overpicnum = sec->ceilingpicnum;
+                    wal.overpicnum = legacyTileNum(sec->ceilingtexture());
                     continue;
                 }
 
@@ -374,7 +374,7 @@ void JS_InitMirrors(void)
                 mirrorcnt++;
             }
             else
-                wal.overpicnum = sec->ceilingpicnum;
+                wal.overpicnum = legacyTileNum(sec->ceilingtexture());
         }
     }
 
diff --git a/source/games/sw/src/save.cpp b/source/games/sw/src/save.cpp
index 0ded91698..ca4185a78 100644
--- a/source/games/sw/src/save.cpp
+++ b/source/games/sw/src/save.cpp
@@ -1085,7 +1085,8 @@ void DSWActor::Serialize(FSerializer& arc)
 	Super::Serialize(arc);
 	arc("hasuser", hasUser)
 		("tempwall", tempwall)
-		("owner", ownerActor);
+		("owner", ownerActor)
+		("texparam", texparam);
 	if (hasUser) arc("user", user); // only write if defined.
 }
 
diff --git a/source/games/sw/src/sector.cpp b/source/games/sw/src/sector.cpp
index d1ac4ba9c..14a039845 100644
--- a/source/games/sw/src/sector.cpp
+++ b/source/games/sw/src/sector.cpp
@@ -1402,7 +1402,7 @@ void DoChangorMatch(short match)
 
         if (TEST_BOOL1(actor))
         {
-            sectp->ceilingpicnum = SP_TAG4(actor);
+            sectp->ceilingpicnum = SP_TAG4(actor); // sectp->ceilingtexture = actor->texparam;
             sectp->addceilingz(SP_TAG5(actor));
             sectp->ceilingheinum += SP_TAG6(actor);
 
diff --git a/source/games/sw/src/sprite.cpp b/source/games/sw/src/sprite.cpp
index ad11cee54..edaed1eed 100644
--- a/source/games/sw/src/sprite.cpp
+++ b/source/games/sw/src/sprite.cpp
@@ -2009,6 +2009,8 @@ void SpriteSetup(void)
                     // copy tag 7 to tag 6 and pre-shift it
                     SP_TAG6(actor) = SP_TAG7(actor);
                     SP_TAG6(actor) <<= 7;
+                    if (SP_TAG2(actor) >= 0)
+                        actor->texparam = tileGetTextureID(SP_TAG2(actor)); // convert and copy to a safe place. A new map format cannot use the lotag to hold a named texture.
                     change_actor_stat(actor, STAT_CEILING_FLOOR_PIC_OVERRIDE);
                     break;
                 }
@@ -2022,6 +2024,8 @@ void SpriteSetup(void)
 
                 case SECT_CHANGOR:
                 {
+                    if (SP_TAG4(actor) >= 0)
+                        actor->texparam = tileGetTextureID(SP_TAG4(actor)); // convert and copy to a safe place. A new map format cannot use the lotag to hold a named texture.
                     change_actor_stat(actor, STAT_CHANGOR);
                     break;
                 }
diff --git a/source/games/sw/src/swactor.h b/source/games/sw/src/swactor.h
index abe837ef4..a92b9ff17 100644
--- a/source/games/sw/src/swactor.h
+++ b/source/games/sw/src/swactor.h
@@ -16,6 +16,7 @@ public:
 	USER user;
 	walltype* tempwall;	// transient, to replace a hack using a 16 bit sprite field.
 	TObjPtr<DSWActor*> ownerActor;
+	FTextureID texparam;	// only one special variant of ST1 needs this...
 
 	DSWActor() = default;