diff --git a/test_regress/t/t_clk_inp_init.pl b/test_regress/t/t_clk_inp_init.pl
index 079c16ec0..a55bf1710 100755
--- a/test_regress/t/t_clk_inp_init.pl
+++ b/test_regress/t/t_clk_inp_init.pl
@@ -11,7 +11,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 
 compile(make_main => 0,
-        verilator_flags2 => ["-CFLAGS -g3 --exe $Self->{t_dir}/$Self->{name}.cpp"]);
+        verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"]);
 
 execute(check_finished => 1);
 
diff --git a/test_regress/t/t_math_shift_rep.pl b/test_regress/t/t_math_shift_rep.pl
index 664c428d8..b46d46042 100755
--- a/test_regress/t/t_math_shift_rep.pl
+++ b/test_regress/t/t_math_shift_rep.pl
@@ -11,7 +11,6 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 
 compile(
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb -O0'"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_get.pl b/test_regress/t/t_vpi_get.pl
index c3f9a81c0..faf3e678c 100755
--- a/test_regress/t/t_vpi_get.pl
+++ b/test_regress/t/t_vpi_get.pl
@@ -16,7 +16,7 @@ skip("Known compiler limitation")
 compile(
     make_top_shell => 0,
     make_main => 0,
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_get.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_get.cpp"],
     make_pli => 1,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI"],
     v_flags2 => ["+define+USE_VPI_NOT_DPI +define+VERILATOR_COMMENTS"],
diff --git a/test_regress/t/t_vpi_get_public_rw_switch.pl b/test_regress/t/t_vpi_get_public_rw_switch.pl
index 3a5cdf231..2142c3afc 100755
--- a/test_regress/t/t_vpi_get_public_rw_switch.pl
+++ b/test_regress/t/t_vpi_get_public_rw_switch.pl
@@ -20,7 +20,7 @@ pli_filename("t_vpi_get.cpp");
 compile(
     make_top_shell => 0,
     make_main => 0,
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi"
+    verilator_flags2 => ["--exe --vpi"
                          ." --public-flat-rw --prefix Vt_vpi_get --no-l2name"
                          ." $Self->{t_dir}/t_vpi_get.cpp"],
     make_pli => 1,
diff --git a/test_regress/t/t_vpi_memory.pl b/test_regress/t/t_vpi_memory.pl
index 9b95b19c4..c806cf940 100755
--- a/test_regress/t/t_vpi_memory.pl
+++ b/test_regress/t/t_vpi_memory.pl
@@ -19,7 +19,7 @@ compile(
     make_pli => 1,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI"],
     v_flags2 => ["+define+USE_VPI_NOT_DPI"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_memory.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_memory.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_module.pl b/test_regress/t/t_vpi_module.pl
index a1835cb60..fe539483b 100755
--- a/test_regress/t/t_vpi_module.pl
+++ b/test_regress/t/t_vpi_module.pl
@@ -18,7 +18,7 @@ compile(
     make_main => 0,
     make_pli => 1,
     iv_flags2 => ["-g2005-sv"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' +define+USE_DOLLAR_C32 --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_module.cpp"],
+    verilator_flags2 => ["+define+USE_DOLLAR_C32 --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_module.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_module_dpi.pl b/test_regress/t/t_vpi_module_dpi.pl
index 1a546432b..25189b715 100755
--- a/test_regress/t/t_vpi_module_dpi.pl
+++ b/test_regress/t/t_vpi_module_dpi.pl
@@ -22,7 +22,7 @@ compile(
     make_main => 0,
     make_pli => 1,
     iv_flags2 => ["-g2005-sv"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_module.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_module.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_param.pl b/test_regress/t/t_vpi_param.pl
index e5c448b01..feea273d1 100755
--- a/test_regress/t/t_vpi_param.pl
+++ b/test_regress/t/t_vpi_param.pl
@@ -19,7 +19,7 @@ compile(
     make_pli => 1,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI"],
     v_flags2 => ["+define+USE_VPI_NOT_DPI"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_param.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_param.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_time_cb.pl b/test_regress/t/t_vpi_time_cb.pl
index ec265a4e2..ab1608097 100755
--- a/test_regress/t/t_vpi_time_cb.pl
+++ b/test_regress/t/t_vpi_time_cb.pl
@@ -16,7 +16,7 @@ compile(
     sim_time => 2100,
     v_flags2 => ["t/t_vpi_time_cb_c.cpp"],
     iv_flags2 => ["-g2005-sv -DWAVES -DIVERILOG"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_time_cb.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_time_cb.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_unimpl.pl b/test_regress/t/t_vpi_unimpl.pl
index dce3e4aae..2fdc5f638 100755
--- a/test_regress/t/t_vpi_unimpl.pl
+++ b/test_regress/t/t_vpi_unimpl.pl
@@ -13,7 +13,7 @@ scenarios(simulator => 1);
 compile(
     make_top_shell => 0,
     make_main => 0,
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_unimpl.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_unimpl.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_var.pl b/test_regress/t/t_vpi_var.pl
index e9f2bac65..1788e06cd 100755
--- a/test_regress/t/t_vpi_var.pl
+++ b/test_regress/t/t_vpi_var.pl
@@ -17,7 +17,7 @@ compile(
     sim_time => 2100,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI -DWAVES"],
     v_flags2 => ["+define+USE_VPI_NOT_DPI"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_var.cpp"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_var.cpp"],
     );
 
 execute(
diff --git a/test_regress/t/t_vpi_zero_time_cb.pl b/test_regress/t/t_vpi_zero_time_cb.pl
index d2e13ef9c..d29050de0 100755
--- a/test_regress/t/t_vpi_zero_time_cb.pl
+++ b/test_regress/t/t_vpi_zero_time_cb.pl
@@ -16,7 +16,7 @@ compile(
     sim_time => 2100,
     iv_flags2 => ["-g2005-sv -D USE_VPI_NOT_DPI -DWAVES -DIVERILOG"],
     v_flags2 => ["+define+USE_VPI_NOT_DPI"],
-    verilator_flags2 => ["-CFLAGS '-DVL_DEBUG -ggdb' --exe --vpi --no-l2name $Self->{t_dir}/t_vpi_zero_time_cb.cpp -LDFLAGS '-ldl -rdynamic'"],
+    verilator_flags2 => ["--exe --vpi --no-l2name $Self->{t_dir}/t_vpi_zero_time_cb.cpp -LDFLAGS '-ldl -rdynamic'"],
     );
 
 execute(