diff --git a/pkgs/by-name/st/steelix/package.nix b/pkgs/by-name/st/steelix/package.nix
index fdaf8740516f..872fa14bf980 100644
--- a/pkgs/by-name/st/steelix/package.nix
+++ b/pkgs/by-name/st/steelix/package.nix
@@ -1,5 +1,6 @@
 {
   fetchFromGitHub,
+  fetchpatch,
   helix,
   installShellFiles,
   lib,
@@ -18,6 +19,21 @@ rustPlatform.buildRustPackage (finalAttrs: {
     hash = "sha256-qAUODNxHM9K6CrRCFgfBcbqzRd+YHiWn9fEfmIzrohA=";
   };
 
+  # This fork is built from Helix master, whose loader expects tree-sitter
+  # grammars with the platform-native extension (`.dylib` on Darwin) since
+  # helix-editor/helix#14982. We reuse the grammars from `helix.runtime`, built
+  # from the last Helix *release*, which still names them `.so` on Darwin, so
+  # revert that commit to make the loader look for `.so`. Remove once a Helix
+  # release ships #14982 and nixpkgs' grammars switch to `.dylib`.
+  patches = [
+    (fetchpatch {
+      name = "revert-dylib-grammar-extension.patch";
+      url = "https://github.com/helix-editor/helix/commit/430914b298a32653ab1847fdfdf2177a002be04c.patch";
+      revert = true;
+      hash = "sha256-4KUFppkso4/XwNU+mGIgLvl+mJXHZWkmaguYMy8oTyI=";
+    })
+  ];
+
   cargoHash = "sha256-6bu8sIM4So3AbnHHYbh8uu+rEB4IjMQjDgh7/AkLQs0=";
 
   nativeBuildInputs = [
@@ -57,6 +73,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
     license = lib.licenses.mpl20;
     mainProgram = "hx";
     maintainers = with lib.maintainers; [
+      aciceri
       Ra77a3l3-jar
     ];
   };