diff --git a/README.md b/README.md
index e5b62ee..32a5879 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,7 @@ $ stack run coffer-server -- --port=8081
 
 ### Nix
 
-This is the preffered way, install Nix according to the [Nix download page](https://nixos.org/download.html "nix download"). Then execute:
+This is the preffered way, install Nix according to the [Nix download page](https://nixos.org/download/ "nix download"). Then execute:
 
 ```shell
 $ nix develop --extra-experimental-features 'nix-command flakes'
diff --git a/docs/code-style.md b/docs/code-style.md
index fda2190..001e58f 100644
--- a/docs/code-style.md
+++ b/docs/code-style.md
@@ -196,7 +196,7 @@ below for end-of-line comments.
   - You *should* comment every top-level function.
 
 You *must* use [Haddock
-syntax](https://haskell-haddock.readthedocs.io/en/latest/markup.html#markup) in the comments.
+syntax](https://haskell-haddock.readthedocs.io/latest/markup.html#markup) in the comments.
 
 Example:
 
@@ -373,7 +373,7 @@ are partial functions.
 
 As usual, separate type classes with `, ` (comma and a space).
 
-You *should* specify explicit [deriving strategies](https://downloads.haskell.org/ghc/latest/docs/html/users_guide/exts/deriving_strategies.html) in all `deriving` clauses.
+You *should* specify explicit [deriving strategies](https://downloads.haskell.org/ghc/latest/docs/users_guide/exts/deriving_strategies.html) in all `deriving` clauses.
 The `-Wmissing-deriving-strategies ` warning (available since GHC-8.8.1) can help you enforce this rule on CI.
 
 ### Function declaration
@@ -392,7 +392,7 @@ You *should* avoid overly general signatures for functions that are actually
 used with only one type for each parameter. If you need the polymorhic version
 (i.e. if you are instantiating it more than once or if you are writing a
 library), you *may* use GHC's [`SPECIALIZE`
-pragma](https://downloads.haskell.org/ghc/latest/docs/html/users_guide/exts/pragmas.html#specialize-pragma).
+pragma](https://downloads.haskell.org/ghc/latest/docs/users_guide/exts/pragmas.html#specialize-pragma).
 
 You *should* omit parentheses if you have only one constraint.
 
diff --git a/nix/sources.json b/nix/sources.json
index 496d904..8274a39 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -84,16 +84,16 @@
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "xrefcheck": {
-        "branch": "v0.2.2",
+        "branch": "v0.3.0",
         "description": "Check cross-references in repository documents",
         "homepage": "",
         "owner": "serokell",
         "repo": "xrefcheck",
-        "rev": "887803d61c0dfb3726484f00a882101117725c62",
-        "sha256": "1ymlp4g494aig6mzi7bx3r73hpd9c5qsxznka7kjfy2lv0y5gyxy",
+        "rev": "224ccb06fafe88a5040523dc1ad79d8dcfc31133",
+        "sha256": "020fimj5iscidm0zgxgq3xznc5pky608w17svcn59q6srjaqidhc",
         "type": "tarball",
-        "url": "https://github.com/serokell/xrefcheck/archive/887803d61c0dfb3726484f00a882101117725c62.tar.gz",
+        "url": "https://github.com/serokell/xrefcheck/archive/224ccb06fafe88a5040523dc1ad79d8dcfc31133.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz",
-        "version": "0.2.2"
+        "version": "0.3.0"
     }
 }