diff --git a/rubies/4.0.1-modgc b/rubies/4.0.1-modgc
new file mode 100644
index 0000000..1ddc6e5
--- /dev/null
+++ b/rubies/4.0.1-modgc
@@ -0,0 +1,28 @@
+# Ruby 4.0.1 with modular GC support
+# Built from Shopify/ruby fork at the commit corresponding to upstream ruby/ruby v4.0.1 tag.
+# Upstream tag: https://github.com/ruby/ruby/releases/tag/v4.0.1
+# Commit: e04267a14b1a5dea2d2c368e48d41bd3db441f4f
+#
+# This build enables Ruby's experimental modular GC feature, allowing
+# alternative GC implementations to be loaded at runtime.
+#
+# MODULAR GC USAGE:
+#   Ruby is usable as normal in this build, it will use the default Ruby garbage
+#   collector and behave as expected.
+#
+#   To use a modular GC, you need a GC compiled as a shared object with the name
+#   librubygc.<name>.so in the modular GC directory ($PREFIX/lib/ruby/gc/).
+#
+#   Load it at runtime with:
+#     RUBY_GC_LIBRARY=<name> ruby
+#
+
+build_package_modular_gc_install() {
+  log_info "Building modular GC (default)..."
+  capture_command make install-modular-gc MODULAR_GC=default
+}
+
+package_option ruby configure --with-modular-gc="$PREFIX_PATH/lib/ruby/gc"
+
+install_package "openssl-3.4.0" "https://github.com/openssl/openssl/releases/download/openssl-3.4.0/openssl-3.4.0.tar.gz#e15dda82fe2fe8139dc2ac21a36d4ca01d5313c75f99f46c4e8a27571b5486cd" openssl --if needs_openssl:1.0.2-3.x.x
+install_git "ruby-4.0.1-modgc" "https://github.com/Shopify/ruby.git" "v4.0.1" autoconf enable_shared standard modular_gc_install
diff --git a/test/shopify_ruby_definitions/test_ruby_versions.rb b/test/shopify_ruby_definitions/test_ruby_versions.rb
index f232129..708a908 100644
--- a/test/shopify_ruby_definitions/test_ruby_versions.rb
+++ b/test/shopify_ruby_definitions/test_ruby_versions.rb
@@ -19,6 +19,7 @@ def test_ALL_VERSIONS
             (?:\-preview\d*)? # match -preview optionally
                               # preview tag must be before the pshopify tag
             (?:\-pshopify\d*)? # match -pshopify optionally
+            (?:\-modgc)? # match -modgc for modular GC builds
             \z
           }x,
           v,