diff -uNr -X diff-exclude ExtUtils-MakeMaker-6.31.orig/lib/ExtUtils/Command/MM.pm ExtUtils-MakeMaker-6.31/lib/ExtUtils/Command/MM.pm
--- ExtUtils-MakeMaker-6.31.orig/lib/ExtUtils/Command/MM.pm	2007-01-27 18:27:34.000000000 +0000
+++ ExtUtils-MakeMaker-6.31/lib/ExtUtils/Command/MM.pm	2007-01-27 18:36:29.000000000 +0000
@@ -38,30 +38,54 @@
 
   test_harness($verbose, @test_libs);
 
+Run the tests on @ARGV using either Test::Harness or TAPx::Harness. By
+default Test::Harness is used but if the environment variable
+PERL_EUMM_USE_TAPX is set to a true value and TAPx::Harness is installed
+it will be used instead.
+
+The $verbose flag affects the verbosity of the tests. Libraries named in
+@libs will be placed at the front of the tests' @INC include path.
+
 Runs the tests on @ARGV via Test::Harness passing through the $verbose
-flag.  Any @test_libs will be unshifted onto the test's @INC.
+flag. Any @test_libs will be unshifted onto the test's @INC.
 
-@test_libs are run in alphabetical order.
+Tests are run in alphabetical order.
 
 =cut
 
 sub test_harness {
-    require Test::Harness;
-    require File::Spec;
-
-    $Test::Harness::verbose = shift;
-
+    my $verbose = shift;
+    my @libs    = @_;
+    
     # Because Windows doesn't do this for us and listing all the *.t files
     # out on the command line can blow over its exec limit.
     require ExtUtils::Command;
-    my @argv = ExtUtils::Command::expand_wildcards(@ARGV);
+    my @argv = sort { lc $a cmp lc $b } 
+               ExtUtils::Command::expand_wildcards(@ARGV);
 
-    local @INC = @INC;
-    unshift @INC, map { File::Spec->rel2abs($_) } @_;
-    Test::Harness::runtests(sort { lc $a cmp lc $b } @argv);
-}
+    # Consider using TAPx::Harness
+    if ($ENV{PERL_EUMM_USE_TAPX}) {
+        eval "require TAPx::Harness";
+        unless ($@) {
+            my $harness = TAPx::Harness->new( {
+                verbose => $verbose,
+                lib     => \@libs
+            } );
+            
+            $harness->runtests(@argv);
+            return;
+        }
+    }
 
+    # Fallback: use Test::Harness
+    require Test::Harness;
+    require File::Spec;
 
+    local $Test::Harness::verbose = $verbose;
+    local @INC = @INC;
+    unshift @INC, map { File::Spec->rel2abs($_) } @libs;
+    Test::Harness::runtests(@argv);
+}
 
 =item B<pod2man>
 
diff -uNr -X diff-exclude ExtUtils-MakeMaker-6.31.orig/t/xs.t ExtUtils-MakeMaker-6.31/t/xs.t
--- ExtUtils-MakeMaker-6.31.orig/t/xs.t	2007-01-27 18:27:34.000000000 +0000
+++ ExtUtils-MakeMaker-6.31/t/xs.t	2007-01-27 18:26:22.000000000 +0000
@@ -9,7 +9,6 @@
         unshift @INC, 't/lib/';
     }
 }
-chdir 't';
 
 use Test::More;
 use MakeMaker::Test::Utils;