diff --git a/test_regress/t/t_modport_expression_partsel.py b/test_regress/t/t_modport_expression_partsel.py
new file mode 100644
index 000000000..f989a35fb
--- /dev/null
+++ b/test_regress/t/t_modport_expression_partsel.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile()
+
+test.execute()
+
+test.passes()
diff --git a/test_regress/t/t_modport_expression_partsel.v b/test_regress/t/t_modport_expression_partsel.v
new file mode 100644
index 000000000..484b5c604
--- /dev/null
+++ b/test_regress/t/t_modport_expression_partsel.v
@@ -0,0 +1,47 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got=%0x exp=%0x (%s !== %s)\n", `__FILE__,`__LINE__, (gotv), (expv), `"gotv`", `"expv`"); `stop; end while(0);
+// verilog_format: on
+
+interface my_if;
+  logic [15:0] a;
+  logic [7:0] b, c;
+  
+  modport mp1(input .in(a[7:0]), output .out(b));
+  modport mp2(input .in(a[15:8]), output .out(c));
+endinterface
+
+module mod1 (
+  my_if.mp1 i
+);
+  assign i.out = i.in;
+endmodule
+
+module mod2 (
+  my_if.mp2 i
+);
+  assign i.out = ~i.in;
+endmodule
+
+module top ();
+  my_if myIf ();
+  assign myIf.a = 16'habcd;
+
+  mod1 mod1Instance (myIf);
+  mod2 mod2Instance (myIf);
+
+  initial begin
+    #1;
+    `checkh(myIf.b, myIf.a[7:0]);
+    `checkh(myIf.c, ~myIf.a[15:8]);
+    #1;
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule