diff --git a/source/games/sw/src/draw.cpp b/source/games/sw/src/draw.cpp
index a0a8174d5..b015ebec2 100644
--- a/source/games/sw/src/draw.cpp
+++ b/source/games/sw/src/draw.cpp
@@ -811,7 +811,7 @@ static void analyzesprites(tspriteArray& tsprites, const DVector3& viewpos, doub
             else // Otherwise just interpolate the player sprite
             {
                 pp = tActor->user.PlayerP;
-                tsp->pos = interpolatedvalue(pp->opos, pp->PlayerNowPosition, interpfrac);
+                tsp->pos = interpolatedvalue(pp->PlayerPrevPosition, pp->PlayerNowPosition, interpfrac);
                 tsp->angle = pp->angle.interpolatedang(interpfrac);
             }
         }
@@ -1240,7 +1240,7 @@ void drawscreen(PLAYER* pp, double interpfrac, bool sceneonly)
     }
 
     // Get initial player position, interpolating if required.
-    DVector3 tpos = interpolatedvalue(camerapp->opos, camerapp->PlayerNowPosition, interpfrac);
+    DVector3 tpos = interpolatedvalue(camerapp->PlayerPrevPosition, camerapp->PlayerNowPosition, interpfrac);
     if (SyncInput() || pp != Player+myconnectindex)
     {
         tang = camerapp->angle.interpolatedsum(interpfrac);
diff --git a/source/games/sw/src/game.h b/source/games/sw/src/game.h
index a092eda08..72afa70b1 100644
--- a/source/games/sw/src/game.h
+++ b/source/games/sw/src/game.h
@@ -538,7 +538,7 @@ struct PLAYER
 {
     // variable that fit in the sprite or user structure
 
-    DVector3 PlayerNowPosition, opos, oldpos;
+    DVector3 PlayerNowPosition, PlayerPrevPosition, oldpos;
 
     DSWActor* actor;    // this may not be a TObjPtr!
     TObjPtr<DSWActor*> lowActor, highActor;
diff --git a/source/games/sw/src/jsector.cpp b/source/games/sw/src/jsector.cpp
index 7d8ce57cc..0e916f52a 100644
--- a/source/games/sw/src/jsector.cpp
+++ b/source/games/sw/src/jsector.cpp
@@ -598,7 +598,7 @@ void JS_DrawCameras(PLAYER* pp, const DVector3& campos, double smoothratio)
 
                     // If player is dead still then update at MoveSkip4
                     // rate.
-                    if (pp->PlayerNowPosition.X == pp->opos.X && pp->PlayerNowPosition.Y == pp->opos.Y && pp->PlayerNowPosition.Z == pp->opos.Z)
+                    if (pp->PlayerNowPosition.X == pp->PlayerPrevPosition.X && pp->PlayerNowPosition.Y == pp->PlayerPrevPosition.Y && pp->PlayerNowPosition.Z == pp->PlayerPrevPosition.Z)
                         DoCam = true;
 
 
diff --git a/source/games/sw/src/osdcmds.cpp b/source/games/sw/src/osdcmds.cpp
index 6a67800bd..9ef6effe9 100644
--- a/source/games/sw/src/osdcmds.cpp
+++ b/source/games/sw/src/osdcmds.cpp
@@ -58,7 +58,7 @@ void GameInterface::WarpToCoords(double x, double y, double z, DAngle ang)
 {
     Player->PlayerNowPosition = DVector3(x,y,z);
 
-    Player->opos = Player->PlayerNowPosition;
+    Player->PlayerPrevPosition = Player->PlayerNowPosition;
 
     if (ang != DAngle::fromDeg(INT_MIN))
     {
diff --git a/source/games/sw/src/player.cpp b/source/games/sw/src/player.cpp
index 6ce1b12ab..9d3447f0e 100644
--- a/source/games/sw/src/player.cpp
+++ b/source/games/sw/src/player.cpp
@@ -1312,7 +1312,7 @@ void DoPlayerTeleportPause(PLAYER* pp)
 void DoPlayerTeleportToSprite(PLAYER* pp, DVector3& pos, DAngle ang)
 {
     pp->angle.ang = pp->angle.oang = ang;
-	pp->opos = pp->PlayerNowPosition= pos.plusZ(-PLAYER_HEIGHTF);
+	pp->PlayerPrevPosition = pp->PlayerNowPosition= pos.plusZ(-PLAYER_HEIGHTF);
 	pp->oldpos.XY() = pp->PlayerNowPosition.XY();
 
     updatesector(pp->PlayerNowPosition, &pp->cursector);
@@ -1327,7 +1327,7 @@ void DoPlayerTeleportToSprite(PLAYER* pp, DVector3& pos, DAngle ang)
 
 void DoPlayerTeleportToOffset(PLAYER* pp)
 {
-    pp->oldpos.XY() = pp->opos.XY() = pp->PlayerNowPosition.XY();
+    pp->oldpos.XY() = pp->PlayerPrevPosition.XY() = pp->PlayerNowPosition.XY();
 
     updatesector(pp->PlayerNowPosition, &pp->cursector);
     pp->Flags2 |= (PF2_TELEPORTED);
@@ -2163,7 +2163,7 @@ void DoPlayerMove(PLAYER* pp)
         auto sect = pp->cursector;
         if (interpolate_ride)
         {
-            pp->opos.XY() = pp->PlayerNowPosition.XY();
+            pp->PlayerPrevPosition.XY() = pp->PlayerNowPosition.XY();
         }
 		pp->PlayerNowPosition += pp->vect;
         updatesector(pp->PlayerNowPosition, &sect);
@@ -2188,7 +2188,7 @@ void DoPlayerMove(PLAYER* pp)
 
         if (interpolate_ride)
         {
-            pp->opos.XY() = pp->PlayerNowPosition.XY();
+            pp->PlayerPrevPosition.XY() = pp->PlayerNowPosition.XY();
         }
 
         auto save_cstat = actor->spr.cstat;
@@ -2217,7 +2217,7 @@ void DoPlayerMove(PLAYER* pp)
 
     if (interpolate_ride)
     {
-        pp->opos.Z = pp->PlayerNowPosition.Z;
+        pp->PlayerPrevPosition.Z = pp->PlayerNowPosition.Z;
         pp->angle.backup();
     }
 
@@ -3753,7 +3753,7 @@ void PlayerWarpUpdatePos(PLAYER* pp)
     if (Prediction)
         return;
 
-    pp->opos = pp->PlayerNowPosition;
+    pp->PlayerPrevPosition = pp->PlayerNowPosition;
     DoPlayerZrange(pp);
     UpdatePlayerSprite(pp);
 }
@@ -4283,7 +4283,7 @@ void DoPlayerWarpToUnderwater(PLAYER* pp)
 
     pp->PlayerNowPosition.Z = under_act->sector()->ceilingz + 6;
 
-    pp->opos = pp->PlayerNowPosition;
+    pp->PlayerPrevPosition = pp->PlayerNowPosition;
 
     DoPlayerZrange(pp);
     return;
@@ -4359,7 +4359,7 @@ void DoPlayerWarpToSurface(PLAYER* pp)
 
     pp->PlayerNowPosition.Z -= pp->WadeDepth;
 
-    pp->opos = pp->PlayerNowPosition;
+    pp->PlayerPrevPosition = pp->PlayerNowPosition;
 
     return;
 }
@@ -6818,7 +6818,7 @@ void MoveSkipSavePos(void)
     {
         pp = Player + pnum;
 
-        pp->opos = pp->PlayerNowPosition;
+        pp->PlayerPrevPosition = pp->PlayerNowPosition;
         pp->obob_z = pp->bob_z;
         pp->angle.backup();
         pp->horizon.backup();
@@ -7174,7 +7174,7 @@ void InitAllPlayers(void)
     // Initialize all [MAX_SW_PLAYERS] arrays here!
     for (pp = Player; pp < &Player[MAX_SW_PLAYERS]; pp++)
     {
-        pp->PlayerNowPosition = pp->opos = pfirst->PlayerNowPosition;
+        pp->PlayerNowPosition = pp->PlayerPrevPosition = pfirst->PlayerNowPosition;
         pp->angle.ang = pp->angle.oang = pfirst->angle.ang;
         pp->horizon.horiz = pp->horizon.ohoriz = pfirst->horizon.horiz;
         pp->cursector = pfirst->cursector;
@@ -7335,7 +7335,7 @@ void PlayerSpawnPosition(PLAYER* pp)
     ASSERT(spawn_sprite != nullptr);
 
     pp->PlayerNowPosition = spawn_sprite->spr.pos;
-    pp->opos = pp->PlayerNowPosition;
+    pp->PlayerPrevPosition = pp->PlayerNowPosition;
     pp->angle.ang = pp->angle.oang = spawn_sprite->spr.angle;
     pp->setcursector(spawn_sprite->sector());
 
@@ -7344,7 +7344,7 @@ void PlayerSpawnPosition(PLAYER* pp)
     if (pp->PlayerNowPosition.Z > fz - PLAYER_HEIGHTF)
     {
 		pp->PlayerNowPosition.Z = fz - PLAYER_HEIGHTF;
-        pp->opos.Z = pp->PlayerNowPosition.Z;
+        pp->PlayerPrevPosition.Z = pp->PlayerNowPosition.Z;
     }
 }
 
diff --git a/source/games/sw/src/save.cpp b/source/games/sw/src/save.cpp
index 92dbce929..14b58fe96 100644
--- a/source/games/sw/src/save.cpp
+++ b/source/games/sw/src/save.cpp
@@ -574,7 +574,7 @@ FSerializer& Serialize(FSerializer& arc, const char* keyname, PLAYER& w, PLAYER*
 	}
 	if (arc.isReading())
 	{
-		w.opos = w.PlayerNowPosition;
+		w.PlayerPrevPosition = w.PlayerNowPosition;
 		w.ovect = w.vect;
 		w.obob_z = w.bob_z;
 		w.input = {};
diff --git a/source/games/sw/src/sprite.cpp b/source/games/sw/src/sprite.cpp
index 109265272..f397b58f7 100644
--- a/source/games/sw/src/sprite.cpp
+++ b/source/games/sw/src/sprite.cpp
@@ -1544,7 +1544,7 @@ void PreMapCombineFloors(void)
                 if (itsect == dasect)
                 {
                     pp->PlayerNowPosition += dv;
-                    pp->opos.XY() = pp->oldpos.XY() = pp->PlayerNowPosition.XY();
+                    pp->PlayerPrevPosition.XY() = pp->oldpos.XY() = pp->PlayerNowPosition.XY();
                     break;
                 }
             }