diff --git a/build.nix b/build.nix
index 615ff237e5..4ddf83746f 100644
--- a/build.nix
+++ b/build.nix
@@ -62,10 +62,10 @@ in rec {
         inherit evalPackages;
         src = pkgs.haskell-nix.sources."hls-2.2";
       };
-    } // pkgs.lib.optionalAttrs (ghcFromTo "9.0" "9.9") {
-      "hls-28" = tool compiler-nix-name "haskell-language-server" {
+    } // pkgs.lib.optionalAttrs (ghcFromTo "9.0" "9.11") {
+      "hls-29" = tool compiler-nix-name "haskell-language-server" {
         inherit evalPackages;
-        src = pkgs.haskell-nix.sources."hls-2.8";
+        src = pkgs.haskell-nix.sources."hls-2.9";
       };
     })
   );
diff --git a/flake.lock b/flake.lock
index b840f10928..4786c4bb47 100644
--- a/flake.lock
+++ b/flake.lock
@@ -286,6 +286,23 @@
         "type": "github"
       }
     },
+    "hls-2.9": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1718469202,
+        "narHash": "sha256-THXSz+iwB1yQQsr/PY151+2GvtoJnTIB2pIQ4OzfjD4=",
+        "owner": "haskell",
+        "repo": "haskell-language-server",
+        "rev": "40891bccb235ebacce020b598b083eab9dda80f1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "haskell",
+        "ref": "2.9.0.0",
+        "repo": "haskell-language-server",
+        "type": "github"
+      }
+    },
     "hpc-coveralls": {
       "flake": false,
       "locked": {
@@ -574,6 +591,7 @@
         "hls-2.6": "hls-2.6",
         "hls-2.7": "hls-2.7",
         "hls-2.8": "hls-2.8",
+        "hls-2.9": "hls-2.9",
         "hpc-coveralls": "hpc-coveralls",
         "hydra": "hydra",
         "iserv-proxy": "iserv-proxy",
diff --git a/flake.nix b/flake.nix
index 6c88d07f33..dcc7d4d29b 100644
--- a/flake.nix
+++ b/flake.nix
@@ -24,6 +24,7 @@
     "hls-2.6" = { url = "github:haskell/haskell-language-server/2.6.0.0"; flake = false; };
     "hls-2.7" = { url = "github:haskell/haskell-language-server/2.7.0.0"; flake = false; };
     "hls-2.8" = { url = "github:haskell/haskell-language-server/2.8.0.0"; flake = false; };
+    "hls-2.9" = { url = "github:haskell/haskell-language-server/2.9.0.0"; flake = false; };
     hydra.url = "hydra";
     hackage = {
       url = "github:input-output-hk/hackage.nix";