diff --git a/extract/ExtHier.c b/extract/ExtHier.c
index df5f64ac..2761116b 100644
--- a/extract/ExtHier.c
+++ b/extract/ExtHier.c
@@ -152,7 +152,11 @@ extHierSubstrate(ha, use, x, y)
 	subArea.r_ur.p_y = subArea.r_ll.p_y + 1;
     }
     else
-	subArea = ha->ha_subArea;
+    {
+	/* Check area under all of the subcircuit (not just the part	*/
+	/* in the current interaction area).				*/
+	GeoTransRect(&use->cu_transform, &use->cu_def->cd_bbox, &subArea.r_ll);
+    }
   
     for (pNum = PL_TECHDEPBASE; pNum < DBNumPlanes; pNum++)
     {