diff --git a/Makefile.PL b/Makefile.PL
index 7cf1284..d1fb261 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -20,6 +20,7 @@ use strict;
 use warnings;
 use ExtUtils::MakeMaker;
 use File::Spec;
+use Config;
 use Cwd;
 
 my %PREREQ_PM = (
@@ -30,6 +31,7 @@ my %PREREQ_PM = (
 
 my %BUILD_REQ = (
   'gobject-introspection-1.0' => '0.10.0',
+  'libffi'                    => '3.0.0',
 );
 
 my $dep_success = eval <<__EOE__;
@@ -55,6 +57,18 @@ if (!$cfg_success) {
   exit 0;
 }
 
+$cfg_success = eval {
+  my %cfg_ffi = ExtUtils::PkgConfig->find (
+    "libffi >= $BUILD_REQ{'libffi'}");
+  $cfg{cflags} .= " $cfg_ffi{cflags}";
+  $cfg{libs} .= " $cfg_ffi{libs}";
+  1;
+};
+if (!$cfg_success) {
+  warn $@;
+  exit 0;
+}
+
 my @xs_files = qw(GObjectIntrospection.xs);
 
 my %pm_files = (
@@ -118,42 +132,108 @@ sub compile_test_libraries {
       ExtUtils::PkgConfig->find ('cairo-gobject') :
       (cflags => '', libs => '');
     my %gio_flags = ExtUtils::PkgConfig->find ('gio-2.0');
-    my %glib_flags = ExtUtils::PkgConfig->find ('glib-2.0');
-
-       !system (qq(gcc -shared -fPIC -g \\
-                   $cairo_flags{cflags} $cairo_gobject_flags{cflags} $gio_flags{cflags} \\
-                   $testsdir/regress.c \\
-                   $cairo_flags{libs} $cairo_gobject_flags{libs} $gio_flags{libs} \\
-                   -o libregress.so 1>/dev/null 2>/dev/null))
-    && !system (qq(LD_LIBRARY_PATH=$build_dir:\$LD_LIBRARY_PATH \\
-                   g-ir-scanner \\
-                   --include=cairo-1.0 --include=Gio-2.0 \\
-                   --namespace=Regress --nsversion=1.0 \\
-                   --quiet --warn-all --warn-error \\
-                   --library=regress \\
-                   --output=Regress-1.0.gir \\
-                   $testsdir/regress.h $testsdir/regress.c \\
-                   1>/dev/null 2>/dev/null))
-    && !system (qq(g-ir-compiler Regress-1.0.gir -o Regress-1.0.typelib \\
-                   1>/dev/null 2>/dev/null))
-    && !system (qq(gcc -shared -fPIC -g \\
-                   $glib_flags{cflags} \\
-                   $testsdir/gimarshallingtests.c \\
-                   $glib_flags{libs} \\
-                   -o libgimarshallingtests.so 1>/dev/null 2>/dev/null))
-    && !system (qq(LD_LIBRARY_PATH=$build_dir:\$LD_LIBRARY_PATH \\
-                   g-ir-scanner \\
-                   --include=GObject-2.0 \\
-                   --namespace=GIMarshallingTests \\
-                   --symbol-prefix=gi_marshalling_tests --nsversion=1.0 \\
-                   --quiet --warn-all --warn-error \\
-                   --library=gimarshallingtests \\
-                   --output=GIMarshallingTests-1.0.gir \\
-                   $testsdir/gimarshallingtests.h $testsdir/gimarshallingtests.c \\
-                   1>/dev/null 2>/dev/null))
-    && !system (qq(g-ir-compiler GIMarshallingTests-1.0.gir \\
-                   -o GIMarshallingTests-1.0.typelib 1>/dev/null 2>/dev/null))
+    my $optimize = '';
+
+    if (grep /^OPTIMIZE=.+/, @ARGV) {
+        # XXX: Workaround Glib built with atomic intrinsics by adding OPTIMIZE to
+        #      CFLAGS (without -march=pentium you get undefined references to
+        #      __sync_fetch_and_sub_4 for example).
+        $optimize = ((grep /^OPTIMIZE=.+/, @ARGV)[0] =~ /^OPTIMIZE=(.+)$/)[0];
+    }
+
+    my @commands;
+    my $c_flags = qq(-shared -fPIC $optimize);
+    my $gir_cmd = qq(LD_LIBRARY_PATH=$build_dir:\$LD_LIBRARY_PATH g-ir-scanner);
+    my $prefix = q();
+    my $pipe = qq(1>/dev/null 2>/dev/null);
+
+    if ($^O eq 'MSWin32') {
+      my @path = File::Spec->path;
+      my $found = 0;
+
+      foreach my $base ( map { File::Spec->catfile($_, 'g-ir-scanner') } @path ) {
+        if ( -f $base ) {
+          $gir_cmd = qq(python $base);
+          $found = 1;
+          last;
+        }
+      }
+
+      return 0 if (!$found);
+
+      $c_flags = qq(-shared $optimize);
+      $pipe = qq(1>NUL 2>NUL);
+      # XXX: We need the lib prefix for --library argument to G-O-I on Win32,
+      #      else DLL resolution fails...
+      $prefix = 'lib';
+    }
+    
+    push(@commands,
+         qq(gcc $c_flags -g \\
+            $cairo_flags{cflags} $cairo_gobject_flags{cflags} $gio_flags{cflags} \\
+            $testsdir/regress.c \\
+            $cairo_flags{libs} $cairo_gobject_flags{libs} $gio_flags{libs} \\
+            -o libregress.$Config{dlext} $pipe));
+    push(@commands,
+         qq($gir_cmd \\
+            --include=cairo-1.0 --include=Gio-2.0 \\
+            --namespace=Regress --nsversion=1.0 \\
+            --quiet --warn-all --warn-error \\
+            --library=${prefix}regress \\
+            --output=Regress-1.0.gir \\
+            $testsdir/regress.h $testsdir/regress.c \\
+            $pipe));
+    push(@commands,
+         qq(g-ir-compiler Regress-1.0.gir -o Regress-1.0.typelib \\
+            $pipe));
+    push(@commands,
+         qq(gcc $c_flags -g \\
+            $gio_flags{cflags} \\
+            $testsdir/gimarshallingtests.c \\
+            $gio_flags{libs} \\
+            -o libgimarshallingtests.$Config{dlext} $pipe));
+    push(@commands,
+         qq($gir_cmd \\
+            --include=Gio-2.0 \\
+            --namespace=GIMarshallingTests \\
+            --symbol-prefix=gi_marshalling_tests --nsversion=1.0 \\
+            --quiet --warn-all --warn-error \\
+            --library=${prefix}gimarshallingtests \\
+            --output=GIMarshallingTests-1.0.gir \\
+            $testsdir/gimarshallingtests.h $testsdir/gimarshallingtests.c \\
+            $pipe));
+    push(@commands,
+         qq(g-ir-compiler GIMarshallingTests-1.0.gir \\
+            -o GIMarshallingTests-1.0.typelib $pipe));
+
+    if ($^O eq 'MSWin32') {
+      my $path = $ENV{PATH};
+      
+      # XXX: G-O-I defaults to CC=cc
+      $ENV{CC} = 'gcc' if (!defined $ENV{CC});
+      $ENV{PATH} .= ';' . $build_dir;
+
+      foreach my $command (@commands) {
+        # XXX: Cmd.exe do not support \ as line break ...
+        $command =~ s/\\\n//mg;
+        $command =~ s/\s\s+/ /mg;
+
+        system($command) == 0 or return 0;
+      }
+      
+      $ENV{PATH} = $path;
+    }
+    else {
+      foreach my $command (@commands) {
+        system($command) == 0 or return 0;
+      }
+    }
+
+    1;
   };
+  if ($@) {
+    print "\n\n$ \n";
+  }
 
   print $success ? "OK\n" : "not OK\n";
 
@@ -164,8 +244,15 @@ package MY; # so that "SUPER" works right
 
 sub test {
   my $inherited = shift->SUPER::test(@_);
-  # put "build" into LD_LIBRARY_PATH for the tests
-  $inherited =~ s/(test_dynamic :: pure_all)\n\t/$1\n\tLD_LIBRARY_PATH=\${LD_LIBRARY_PATH}:build /;
+  if ($^O eq 'MSWin32') {
+    # put "build" into PATH for the tests
+    # FIXME: Might need tweaking for nmake...
+    $inherited =~ s/(test_dynamic :: pure_all\n\t)/.IMPORT: PATH\nPATH += ;build\n.EXPORT: PATH\n$1/;
+  }
+  else {
+    # put "build" into LD_LIBRARY_PATH for the tests
+    $inherited =~ s/(test_dynamic :: pure_all)\n\t/$1\n\tLD_LIBRARY_PATH=\${LD_LIBRARY_PATH}:build /;
+  }
   $inherited;
 }
 
diff --git a/t/inc/setup.pl b/t/inc/setup.pl
index 039f33d..cb2a3a9 100644
--- a/t/inc/setup.pl
+++ b/t/inc/setup.pl
@@ -1,14 +1,27 @@
+use Config;
 use Glib::Object::Introspection;
 use Test::More;
 
-unless (-e 'build/libregress.so' && -e 'build/libgimarshallingtests.so') {
+unless (-e qq(build/libregress.$Config{dlext}) &&
+        -e qq(build/libgimarshallingtests.$Config{dlext}))
+{
   plan skip_all => 'Need the test libraries';
 }
 
-unless (defined $ENV{LD_LIBRARY_PATH} &&
-        $ENV{LD_LIBRARY_PATH} =~ m/\bbuild\b/)
-{
-  plan skip_all => 'Need "build" in LD_LIBRARY_PATH';
+if ($^O eq 'MSWin32') {
+  # FIXME: Not sure how to get this to actually work with dmake
+  unless (defined $ENV{PATH} &&
+          $ENV{PATH} =~ m/\bbuild\b/)
+  {
+    plan skip_all => 'Need "build" in PATH';
+  }
+}
+else {
+  unless (defined $ENV{LD_LIBRARY_PATH} &&
+          $ENV{LD_LIBRARY_PATH} =~ m/\bbuild\b/)
+  {
+    plan skip_all => 'Need "build" in LD_LIBRARY_PATH';
+  }
 }
 
 Glib::Object::Introspection->setup(