diff --git a/MANIFEST b/MANIFEST
index b9f6985e..fbaf5768 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -120,6 +120,7 @@ t/fileline.t
 t/filter.t
 t/foreach.t
 t/format.t
+t/grammar-factory.t
 t/html.t
 t/image.t
 t/include.t
@@ -241,6 +242,7 @@ t/vmethods/text.t
 t/while.t
 t/wrap.t
 t/wrapper.t
+t/zz-grammar-factory-leak.t
 t/zz-plugin-cycle.t
 t/zz-plugin-leak-gh-213.t
 t/zz-plugin-leak-rt-46691.t
diff --git a/t/grammar-factory.t b/t/grammar-factory.t
new file mode 100644
index 00000000..2a7b65f0
--- /dev/null
+++ b/t/grammar-factory.t
@@ -0,0 +1,120 @@
+#============================================================= -*-perl-*-
+#
+# t/grammar-factory.t
+#
+# Test Template::Grammar factory registration and cleanup lifecycle.
+# This test does NOT require Test::LeakTrace and runs for all users.
+#
+# Written by Nicolas R. <atoomic@cpan.org>
+#
+# This is free software; you can redistribute it and/or modify it
+# under the same terms as Perl itself.
+#
+#========================================================================
+
+use strict;
+use warnings;
+use lib qw( t/lib ./lib ../lib ../blib/arch );
+
+use Test::More tests => 9;
+
+use Template;
+use Template::Grammar;
+
+# -----------------------------------------------------------------------
+# Test 1-3: Grammar basic lifecycle
+# -----------------------------------------------------------------------
+
+{
+    my $g = Template::Grammar->new();
+    isa_ok( $g, 'Template::Grammar', 'new Grammar object' );
+
+    my $factory = bless { id => 1 }, 'TestFactory';
+    my $result = $g->install_factory($factory);
+    is( $result, $factory, 'install_factory returns the factory' );
+
+    undef $g;
+    pass("Grammar DESTROY completes without error");
+}
+
+# -----------------------------------------------------------------------
+# Test 4-5: Multiple Grammar instances share the factory
+# -----------------------------------------------------------------------
+
+{
+    my $g1 = Template::Grammar->new();
+    my $g2 = Template::Grammar->new();
+
+    my $factory = bless { id => 2 }, 'TestFactory';
+    $g1->install_factory($factory);
+    $g2->install_factory($factory);
+
+    undef $g1;
+    pass("first Grammar can be destroyed while second holds factory");
+
+    undef $g2;
+    pass("second Grammar destruction completes cleanly");
+}
+
+# -----------------------------------------------------------------------
+# Test 6-7: Template processing works correctly after factory cleanup
+# -----------------------------------------------------------------------
+
+my $tmpl = <<'EOT';
+[% name %] is [% age %]
+EOT
+
+{
+    my $out = '';
+    my $tt = Template->new();
+    $tt->process( \$tmpl, { name => 'Alice', age => 30 }, \$out );
+    is( $out, "Alice is 30\n", "basic template processing works" );
+}
+
+# After tt is destroyed, create a new one — factory should be re-established
+{
+    my $out = '';
+    my $tt = Template->new();
+    $tt->process( \$tmpl, { name => 'Bob', age => 25 }, \$out );
+    is( $out, "Bob is 25\n", "template processing works after previous Template destroyed" );
+}
+
+# -----------------------------------------------------------------------
+# Test 8-9: FOREACH reproducer from issue #147
+# -----------------------------------------------------------------------
+
+my $foreach_tmpl = <<'EOT';
+[% FOREACH item IN data -%]
+[% item.val %]
+[% FOREACH data IN item.stuff -%]
+... one item
+[% END -%]
+[% END -%]
+EOT
+
+{
+    my $out = '';
+    my $tt = Template->new();
+    my $vars = {
+        data => [
+            { val => 'hello' }
+        ]
+    };
+    $tt->process( \$foreach_tmpl, $vars, \$out );
+    is( $out, "hello\n", "FOREACH template without nested data" );
+}
+
+{
+    my $out = '';
+    my $tt = Template->new();
+    my $vars = {
+        data => [
+            {
+                val   => 'world',
+                stuff => [ { name => 'bob' } ]
+            }
+        ]
+    };
+    $tt->process( \$foreach_tmpl, $vars, \$out );
+    is( $out, "world\n... one item\n", "FOREACH template with nested data" );
+}
diff --git a/t/zz-grammar-factory-leak.t b/t/zz-grammar-factory-leak.t
new file mode 100644
index 00000000..de9c214c
--- /dev/null
+++ b/t/zz-grammar-factory-leak.t
@@ -0,0 +1,172 @@
+#============================================================= -*-perl-*-
+#
+# t/zz-grammar-factory-leak.t
+#
+# Test that Template::Grammar properly cleans up the factory singleton
+# to avoid memory leaks.  Resolves issue #147 (RT #49456).
+#
+# Written by Nicolas R. <atoomic@cpan.org>
+#
+# This is free software; you can redistribute it and/or modify it
+# under the same terms as Perl itself.
+#
+#========================================================================
+
+use strict;
+use warnings;
+use lib qw( t/lib ./lib ../lib ../blib/arch );
+
+use Test::More;
+
+BEGIN {
+    unless ( $ENV{AUTOMATED_TESTING} or $ENV{RELEASE_TESTING} ) {
+        plan( skip_all => "Developer tests not required for installation" );
+    }
+
+    eval { require Test::LeakTrace; Test::LeakTrace->import(); 1 }
+        or plan( skip_all => 'Test::LeakTrace not installed' );
+}
+
+use Template;
+use Template::Grammar;
+
+plan tests => 8;
+
+# -----------------------------------------------------------------------
+# Test 1-2: Basic factory cleanup on Grammar destruction
+# -----------------------------------------------------------------------
+
+{
+    my $grammar = Template::Grammar->new();
+    isa_ok( $grammar, 'Template::Grammar', 'Grammar object created' );
+
+    # install a factory and verify it sticks
+    my $fake_factory = bless {}, 'FakeFactory';
+    $grammar->install_factory($fake_factory);
+
+    # destroying Grammar should clear the factory
+    undef $grammar;
+    pass("Grammar destruction clears factory without error");
+}
+
+# -----------------------------------------------------------------------
+# Test 3-4: Template processing should not leak
+# Reproduces the original bug report from RT #49456 / issue #147
+# -----------------------------------------------------------------------
+
+my $template_text = <<'EOT';
+[% FOREACH item IN data -%]
+[% item.val %]
+[% FOREACH data IN item.stuff -%]
+... one item
+[% END -%]
+[% END -%]
+EOT
+
+my $vars_simple = {
+    data => [
+        { val => 'value1' }
+    ]
+};
+
+my $vars_with_stuff = {
+    data => [
+        {
+            val   => 'value2',
+            stuff => [ { name => 'bob' } ]
+        }
+    ]
+};
+
+{
+    # First call may allocate the grammar singleton -- run once to warm up
+    my $tt_warmup = Template->new();
+    my $warmup_out = '';
+    $tt_warmup->process( \$template_text, $vars_simple, \$warmup_out );
+}
+
+# The second process call should not leak
+no_leaks_ok {
+    my $out = '';
+    local $@;
+    my $tt = Template->new();
+    eval { $tt->process( \$template_text, $vars_simple, \$out ); };
+} "no leak when processing simple template (issue #147)";
+
+no_leaks_ok {
+    my $out = '';
+    local $@;
+    my $tt = Template->new();
+    eval { $tt->process( \$template_text, $vars_with_stuff, \$out ); };
+} "no leak when processing template with nested data";
+
+# -----------------------------------------------------------------------
+# Test 5-6: Multiple Template instances should not leak
+# -----------------------------------------------------------------------
+
+{
+    # warm up
+    for (1..2) {
+        my $tt = Template->new();
+        my $out = '';
+        $tt->process( \$template_text, $vars_simple, \$out );
+    }
+}
+
+no_leaks_ok {
+    my $out = '';
+    local $@;
+    my $tt = Template->new();
+    eval { $tt->process( \$template_text, $vars_simple, \$out ) };
+    my $tt2 = Template->new();
+    eval { $tt2->process( \$template_text, $vars_with_stuff, \$out ) };
+} "no leak with multiple Template instances in same scope";
+
+no_leaks_ok {
+    for my $i (1..3) {
+        my $out = '';
+        local $@;
+        my $tt = Template->new();
+        eval { $tt->process( \$template_text, $vars_simple, \$out ) };
+    }
+} "no leak when creating and destroying Template objects in a loop";
+
+# -----------------------------------------------------------------------
+# Test 7: Factory is properly shared and cleaned
+# -----------------------------------------------------------------------
+
+{
+    my $g1 = Template::Grammar->new();
+    my $g2 = Template::Grammar->new();
+
+    my $factory1 = bless {}, 'FakeFactory';
+    $g1->install_factory($factory1);
+    $g2->install_factory($factory1);
+
+    undef $g1;
+    # factory should still be alive because g2 holds it
+    pass("partial Grammar destruction does not crash");
+
+    undef $g2;
+    # now factory should be cleaned up
+}
+
+# -----------------------------------------------------------------------
+# Test 8: Output correctness after factory cleanup
+# -----------------------------------------------------------------------
+
+{
+    my $out1 = '';
+    {
+        my $tt = Template->new();
+        $tt->process( \$template_text, $vars_simple, \$out1 );
+    }
+    # tt is now destroyed, factory should be cleaned
+
+    my $out2 = '';
+    {
+        my $tt = Template->new();
+        $tt->process( \$template_text, $vars_simple, \$out2 );
+    }
+    is( $out1, $out2, "output is identical across Template lifecycles" );
+}