diff --git a/polymer/eduke32/build/src/polymer.c b/polymer/eduke32/build/src/polymer.c
index 078c6049f..3c46b9ebc 100644
--- a/polymer/eduke32/build/src/polymer.c
+++ b/polymer/eduke32/build/src/polymer.c
@@ -2997,7 +2997,7 @@ static void         polymer_updatewall(int16_t wallnum)
         }
 
         if (wal->ypanning)
-            // white
+            // white (but not 1-way)
             ypancoef = calc_ypancoef(wal->ypanning, curpicnum, !(wal->cstat & 4));
         else
             ypancoef = 0;
@@ -3186,7 +3186,7 @@ static void         polymer_updatewall(int16_t wallnum)
                 curpicnum = walloverpicnum;
 
                 if (wal->ypanning)
-                    // mask
+                    // mask / 1-way
                     ypancoef = calc_ypancoef(wal->ypanning, curpicnum, 0);
                 else
                     ypancoef = 0;
diff --git a/polymer/eduke32/build/src/polymost.c b/polymer/eduke32/build/src/polymost.c
index e1a289fdb..87e523996 100644
--- a/polymer/eduke32/build/src/polymost.c
+++ b/polymer/eduke32/build/src/polymost.c
@@ -3026,6 +3026,8 @@ static void polymost_drawalls(int32_t bunch)
 
         if ((nextsectnum < 0) || (wal->cstat&32))   //White/1-way wall
         {
+            const int32_t maskingOneWay = (nextsectnum >= 0 && (wal->cstat&32));
+
             if (nextsectnum < 0) globalpicnum = wal->picnum; else globalpicnum = wal->overpicnum;
             globalshade = wal->shade; globalpal = (int32_t)((uint8_t)wal->pal);
             globvis = globalvisibility;
@@ -3036,8 +3038,8 @@ static void polymost_drawalls(int32_t bunch)
             if (nextsectnum >= 0) { if (!(wal->cstat&4)) i = nextsec->ceilingz; else i = sec->ceilingz; }
             else { if (!(wal->cstat&4)) i = sec->ceilingz;     else i = sec->floorz; }
 
-            // white
-            calc_ypanning(i, ryp0, ryp1, x0, x1, wal->ypanning, wal->yrepeat, !(wal->cstat&4));
+            // white / 1-way
+            calc_ypanning(i, ryp0, ryp1, x0, x1, wal->ypanning, wal->yrepeat, !maskingOneWay && !(wal->cstat&4));
 
             if (wal->cstat&8) //xflip
             {