diff --git a/polymer/eduke32/build/src/polymost.c b/polymer/eduke32/build/src/polymost.c
index 9344d778b..f63dc93af 100644
--- a/polymer/eduke32/build/src/polymost.c
+++ b/polymer/eduke32/build/src/polymost.c
@@ -2374,7 +2374,8 @@ skip: ;
 
         int const ni = vsp[i].n;
 
-        if ((vsp[i].ctag == vsp[ni].ctag) && (vsp[i].ftag == vsp[ni].ftag))
+        if ((vsp[i].ctag == vsp[ni].ctag) && (vsp[i].ftag == vsp[ni].ftag) &&
+            ((vsp[ni].cy[1] <= vsp[i].cy[1]) || (vsp[ni].fy[1] >= vsp[i].fy[1])))
         {
             vsp[i].cy[1] = vsp[ni].cy[1];
             vsp[i].fy[1] = vsp[ni].fy[1];