diff --git a/resis/ResRex.c b/resis/ResRex.c
index e34bfefa..a1c98d9e 100644
--- a/resis/ResRex.c
+++ b/resis/ResRex.c
@@ -575,6 +575,9 @@ resSubcircuitFunc(cellDef, rdata)
     CellDef *cellDef;
     ResisData *rdata;
 {
+    if ((cellDef->cd_flags & CDINTERNAL) == CDINTERNAL)
+	return 0;
+
     if (cellDef != rdata->mainDef)
 	if (DBIsSubcircuit(cellDef))
 	    ExtResisForDef(cellDef, rdata);