diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index c5878a27e..9e3733dfa 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -806,6 +806,11 @@ sub clean {
     }
 }
 
+sub clean_objs {
+    my $self = (ref $_[0] ? shift : $Self);
+    system("rm", "-rf", glob("$self->{obj_dir}/*"));
+}
+
 sub compile_vlt_cmd {
     my $self = (ref $_[0]? shift : $Self);
     my %param = (%{$self}, @_);  # Default arguments are from $self
diff --git a/test_regress/t/t_flag_build_cmake.pl b/test_regress/t/t_flag_build_cmake.pl
index a58be70f6..1c189d3c3 100755
--- a/test_regress/t/t_flag_build_cmake.pl
+++ b/test_regress/t/t_flag_build_cmake.pl
@@ -12,6 +12,11 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 top_filename("t/t_flag_make_cmake.v");
 
+# This test seems broken as the CMake build invoked by Verilator itself
+# invokes Verilator.. (See #2280). Strangely though it passes when built
+# from clean, so nuke it:
+clean_objs();
+
 compile(  # Don't call cmake nor gmake from driver.pl
     verilator_make_cmake => 0,
     verilator_make_gmake => 0,
diff --git a/test_regress/t/t_flag_verilate.pl b/test_regress/t/t_flag_verilate.pl
index c28d235b6..b523b77e3 100755
--- a/test_regress/t/t_flag_verilate.pl
+++ b/test_regress/t/t_flag_verilate.pl
@@ -12,6 +12,11 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 top_filename("t/t_flag_make_cmake.v");
 
+# We expect below that Vt_flag_verilate.mk and others are not in the build
+# tree already when doing --no-verilate, so we must remove them when
+# re-running the test.
+clean_objs();
+
 compile(  # Don't call cmake nor gmake from driver.pl. Nothing should be done here.
     verilator_make_cmake => 0,
     verilator_make_gmake => 0,