diff --git a/polymer/eduke32/build/src/polymer.c b/polymer/eduke32/build/src/polymer.c
index 452c139e2..a51d6a865 100644
--- a/polymer/eduke32/build/src/polymer.c
+++ b/polymer/eduke32/build/src/polymer.c
@@ -2467,6 +2467,8 @@ static void         polymer_updatewall(int16_t wallnum)
             ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
             if (ypancoef < tilesizy[curpicnum])
                 ypancoef *= 2;
+            if (curypanning > 256 - (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef))
+                curypanning -= (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef);
             ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
         }
         else
@@ -2537,6 +2539,8 @@ static void         polymer_updatewall(int16_t wallnum)
                 ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                 if (ypancoef < tilesizy[curpicnum])
                     ypancoef *= 2;
+                if (curypanning > 256 - (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef))
+                    curypanning -= (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef);
                 ypancoef *= (float)(curypanning) / (256.0f * (float)(tilesizy[curpicnum]));
             }
             else
@@ -2622,6 +2626,8 @@ static void         polymer_updatewall(int16_t wallnum)
                 ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                 if (ypancoef < tilesizy[curpicnum])
                     ypancoef *= 2;
+                if (curypanning > 256 - (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef))
+                    curypanning -= (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef);
                 ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
             }
             else
@@ -2672,6 +2678,8 @@ static void         polymer_updatewall(int16_t wallnum)
                     ypancoef = (float)(pow2long[picsiz[curpicnum] >> 4]);
                     if (ypancoef < tilesizy[curpicnum])
                         ypancoef *= 2;
+                    if (curypanning > 256 - (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef))
+                        curypanning -= (ypancoef - tilesizy[curpicnum]) * (256.0f / ypancoef);
                     ypancoef *= (float)(wal->ypanning) / (256.0f * (float)(tilesizy[curpicnum]));
                 }
                 else