diff --git a/polymer/eduke32/source/sector.c b/polymer/eduke32/source/sector.c
index 40c29daf2..ae35c4956 100644
--- a/polymer/eduke32/source/sector.c
+++ b/polymer/eduke32/source/sector.c
@@ -569,6 +569,9 @@ void G_OperateSectors(int32_t sn, int32_t ii)
                 else wallfind[1] = i;
             }
 
+        if (wallfind[1] == -1)
+            return;
+
         for (j=0; j<2; j++)
         {
             if ((wall[wallfind[j]].x == dax) && (wall[wallfind[j]].y == day))