diff --git a/internal/core/format.go b/internal/core/format.go
index d64b855be..5faf24bbe 100755
--- a/internal/core/format.go
+++ b/internal/core/format.go
@@ -53,6 +53,11 @@ var CommentsByNormedExt = map[string]map[string]string{
 		"blockStart": `(\{-.*)`,
 		"blockEnd":   `(.*-\})`,
 	},
+	".nix": {
+		"inline":     `(#.+)`,
+		"blockStart": `(/\*.*)`,
+		"blockEnd":   `(.*\*/)`,
+	},
 }
 
 // FormatByExtension associates a file extension with its "normed" extension
@@ -92,6 +97,7 @@ var FormatByExtension = map[string][]string{
 	`\.(?:yaml|yml)$`:  {".yml", "data"},
 	`\.(?:json)$`:      {".json", "data"},
 	`\.(?:toml)$`:      {".toml", "data"},
+	`\.(?:nix)$`:       {".nix", "code"},
 }
 
 // FormatFromExt takes a file extension and returns its [normExt, format]
diff --git a/testdata/features/lint.feature b/testdata/features/lint.feature
index 185b04b59..02754ad56 100755
--- a/testdata/features/lint.feature
+++ b/testdata/features/lint.feature
@@ -43,6 +43,16 @@ Feature: Lint
             test.proto:31:1:vale.Annotations:'NOTE' left in text
             """
 
+    Scenario: Lint a Nix file
+        When I lint "test.nix"
+        Then the output should contain exactly:
+            """
+            test.nix:3:3:vale.Annotations:'NOTE' left in text
+            test.nix:7:5:vale.Annotations:'XXX' left in text
+            test.nix:10:6:vale.Annotations:'NOTE' left in text
+            test.nix:17:7:vale.Annotations:'TODO' left in text
+            """
+
     Scenario: Lint an Org file
         When I lint "test.org"
         Then the output should contain exactly:
diff --git a/testdata/fixtures/formats/test.nix b/testdata/fixtures/formats/test.nix
new file mode 100644
index 000000000..2b0a4734b
--- /dev/null
+++ b/testdata/fixtures/formats/test.nix
@@ -0,0 +1,30 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+# NOTE: This is a sample Nix configuration file
+let
+  myVar = "hello world";
+  
+  # XXX: This needs to be fixed later
+  brokenFunction = x: y: x + y + 1;
+  
+  /* NOTE: Multi-line comment
+     that spans multiple lines
+  */
+  myPackage = pkgs.stdenv.mkDerivation {
+    pname = "example";
+    version = "1.0.0";
+    
+    # TODO: Add proper source
+    src = ./.;
+    
+    buildPhase = ''
+      echo "Building..."
+    '';
+  };
+in
+{
+  inherit myPackage;
+  
+  # should not match in code
+  xxx = "XXX";
+}