3 files changed, 6 insertions, 0 deletions
diff --git a/t/TEST b/t/TEST
index fc37118770..6d842d0859 100755
--- a/t/TEST
+++ b/t/TEST
@@ -82,6 +82,7 @@ my %temp_no_core =
 my @bad_env_vars = qw(
     PERL5LIB PERLLIB PERL5OPT
     PERL_YAML_BACKEND PERL_JSON_BACKEND
+    PERL_USE_UNSAFE_INC
 );
 
 for my $envname (@bad_env_vars) {
diff --git a/t/harness b/t/harness
index b46582ddd9..e06c3f8009 100644
--- a/t/harness
+++ b/t/harness
@@ -34,6 +34,9 @@ if ($ARGV[0] && $ARGV[0] eq '-torture') {
 # which live dual lives on CPAN.
 $ENV{PERL_CORE} = 1;
 
+# All our tests should work without . in @INC
+delete $ENV{PERL_USE_UNSAFE_INC};
+
 my (@tests, $re);
 
 # [.VMS]TEST.COM calls harness with empty arguments, so clean-up @ARGV
diff --git a/t/run/runenv.t b/t/run/runenv.t
index fe0d9cd1b6..1b317ce5af 100644
--- a/t/run/runenv.t
+++ b/t/run/runenv.t
@@ -22,6 +22,7 @@ my $FAILURE_CODE = 119;
 delete $ENV{PERLLIB};
 delete $ENV{PERL5LIB};
 delete $ENV{PERL5OPT};
+delete $ENV{PERL_USE_UNSAFE_INC};
 
 
 # Run perl with specified environment and arguments, return (STDOUT, STDERR)
@@ -33,6 +34,7 @@ sub runperl_and_capture {
   delete $ENV{PERLLIB};
   delete $ENV{PERL5LIB};
   delete $ENV{PERL5OPT};
+  delete $ENV{PERL_USE_UNSAFE_INC};
   my $pid = fork;
   return (0, "Couldn't fork: $!") unless defined $pid;   # failure
   if ($pid) {                   # parent