diff --git a/VERSION b/VERSION
index 249ea41..a6a91e5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.230
+1.5.231
diff --git a/tcltk/tclnetgen.c b/tcltk/tclnetgen.c
index 165dba2..10c3355 100644
--- a/tcltk/tclnetgen.c
+++ b/tcltk/tclnetgen.c
@@ -2650,6 +2650,14 @@ _netcmp_verify(ClientData clientData,
 	 else
 	     Fprintf(stdout, "Netlists do not match.\n");
       }
+      else if (automorphisms == -2) {
+	 if (index == EQUIV_IDX)
+	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
+	 else if (index == UNIQUE_IDX)
+	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-2));
+	 else if (index > 0)
+	    Fprintf(stdout, "Circuits match uniquely with port errors.\n");
+      }
       else {
 	 if (automorphisms) {
 	    if (index == EQUIV_IDX)