diff --git a/polymer/eduke32/build/src/polymost.c b/polymer/eduke32/build/src/polymost.c
index 1bf6e87af..aa69be7d4 100644
--- a/polymer/eduke32/build/src/polymost.c
+++ b/polymer/eduke32/build/src/polymost.c
@@ -3466,7 +3466,7 @@ void polymost_drawrooms()
 
     for (int i=0; i<4; i++)
     {
-        int const j = i < n ? i + 1 : 0;
+        int const j = i < 3 ? i + 1 : 0;
 
         if (p[i].z >= SCISDIST)
             p2[n++] = p[i];