diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index 779b64ed2..48650baa1 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -896,6 +896,7 @@ sub compile_vlt_flags {
     unshift @verilator_flags, "--trace-threads 1" if $param{vltmt} && $checkflags =~ /-trace /;
     unshift @verilator_flags, "--trace-threads 2" if $param{vltmt} && $checkflags =~ /-trace-fst /;
     unshift @verilator_flags, "--debug-partition" if $param{vltmt};
+    unshift @verilator_flags, "-CFLAGS -ggdb -LDFLAGS -ggdb" if $opt_gdbsim;
     unshift @verilator_flags, "-CFLAGS -fsanitize=address -LDFLAGS -fsanitize=address" if $param{sanitize};
     unshift @verilator_flags, "--make gmake" if $param{verilator_make_gmake};
     unshift @verilator_flags, "--make cmake" if $param{verilator_make_cmake};