diff --git a/flake.nix b/flake.nix
index 184c5f06d..506125edd 100644
--- a/flake.nix
+++ b/flake.nix
@@ -75,6 +75,7 @@
                 inherit (pkgs) emacs-unstable-pgtk;
                 inherit (pkgs) emacs-git emacs-git-nox;
                 inherit (pkgs) emacs-pgtk;
+                inherit (pkgs) emacs-igc emacs-igc-pgtk;
               };
 
               packages = mkEmacsSet pkgs.emacs;
diff --git a/overlays/emacs.nix b/overlays/emacs.nix
index 1e25d7ef2..365498775 100644
--- a/overlays/emacs.nix
+++ b/overlays/emacs.nix
@@ -146,6 +146,38 @@ let
                               };
                             });
 
+  emacs-igc = let base = (mkGitEmacs "emacs-igc" ../repos/emacs/emacs-igc.json) { };
+                  emacs = emacs-igc;
+              in
+                base.overrideAttrs (
+                  oa: {
+                    buildInputs = oa.buildInputs ++ [ super.mps ];
+                    configureFlags = oa.configureFlags ++ [ "--with-mps=yes" ];
+                    patches = oa.patches ++ [
+                      # XXX: #318
+                      ./bytecomp-revert.patch
+                    ];
+                    passthru = oa.passthru // {
+                      pkgs = oa.passthru.pkgs.overrideScope (eself: esuper: { inherit emacs; });
+                    };
+                  });
+  
+  emacs-igc-pgtk = let base = (mkGitEmacs "emacs-igc-pgtk" ../repos/emacs/emacs-igc.json) { withPgtk = true; };
+                       emacs = emacs-igc-pgtk;
+                   in
+                     base.overrideAttrs (
+                       oa: {
+                         buildInputs = oa.buildInputs ++ [ super.mps ];
+                         configureFlags = oa.configureFlags ++ [ "--with-mps=yes" ];
+                         patches = oa.patches ++ [
+                           # XXX: #318
+                           ./bytecomp-revert.patch
+                         ];
+                         passthru = oa.passthru // {
+                           pkgs = oa.passthru.pkgs.overrideScope (eself: esuper: { inherit emacs; });
+                         };
+                       });
+
   emacs-lsp = (mkGitEmacs "emacs-lsp" ../repos/emacs/emacs-lsp.json) { withTreeSitter = false; };
 
   commercial-emacs = (mkGitEmacs "commercial-emacs" ../repos/emacs/commercial-emacs-commercial-emacs.json) {
@@ -195,6 +227,8 @@ in
 
   inherit commercial-emacs;
 
+  inherit emacs-igc emacs-igc-pgtk;
+
   emacsWithPackagesFromUsePackage = import ../elisp.nix { pkgs = self; };
 
   emacsWithPackagesFromPackageRequires = import ../packreq.nix { pkgs = self; };
diff --git a/repos/emacs/emacs-igc.json b/repos/emacs/emacs-igc.json
new file mode 100644
index 000000000..914364ed9
--- /dev/null
+++ b/repos/emacs/emacs-igc.json
@@ -0,0 +1 @@
+{"type": "github", "owner": "emacs-mirror", "repo": "emacs", "rev": "ef194a1e0e96f91dc7a57efcdf8a81ed716d18e0", "sha256": "01bcxx9h1f613byik1kzpky8d3gi3cq337wdmpzwk6ny797impx5", "version": "20250118.0"}
diff --git a/repos/emacs/update b/repos/emacs/update
index df110bcce..bba9e31ed 100755
--- a/repos/emacs/update
+++ b/repos/emacs/update
@@ -52,6 +52,7 @@ function update_release() {
 
 update_savannah_branch master
 update_release
+update_github_repo emacs-mirror emacs feature/igc igc
 update_github_repo emacs-lsp emacs json-rpc lsp
 update_github_repo commercial-emacs commercial-emacs master commercial-emacs