diff --git a/test_regress/t/t_trace_complex_saif.out b/test_regress/t/t_trace_complex_saif.out
index 5e6c75d5b..875324cb9 100644
--- a/test_regress/t/t_trace_complex_saif.out
+++ b/test_regress/t/t_trace_complex_saif.out
@@ -3,8 +3,8 @@
 (DIRECTION "backward")
 (DESIGN "t")
 (DIVIDER / )
-(TIMESCALE 1 ps)
-(DURATION 59)
+(TIMESCALE 1ps)
+(DURATION 60)
 (INSTANCE top
   (NET
     (clk (T0 35) (T1 25) (TX 0) (TC 11))
diff --git a/test_regress/t/t_trace_complex_saif_threads_1.py b/test_regress/t/t_trace_complex_saif_threads_1.py
new file mode 100755
index 000000000..94b46feb7
--- /dev/null
+++ b/test_regress/t/t_trace_complex_saif_threads_1.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.top_filename = "t/t_trace_complex.v"
+test.golden_filename = "t/t_trace_complex_saif.out"
+
+test.compile(verilator_flags2=['--cc --trace-saif --trace-threads 1'])
+
+test.execute()
+
+test.saif_identical(test.trace_filename, test.golden_filename)
+
+test.passes()
diff --git a/test_regress/t/t_trace_complex_saif_threads_2.py b/test_regress/t/t_trace_complex_saif_threads_2.py
new file mode 100755
index 000000000..13ca4b53d
--- /dev/null
+++ b/test_regress/t/t_trace_complex_saif_threads_2.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.top_filename = "t/t_trace_complex.v"
+test.golden_filename = "t/t_trace_complex_saif.out"
+
+test.compile(verilator_flags2=['--cc --trace-saif --trace-threads 2'])
+
+test.execute()
+
+test.saif_identical(test.trace_filename, test.golden_filename)
+
+test.passes()