diff --git a/README.md b/README.md
index fab887a..4cbdedf 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ designed to work with nixpkgs but also other package sets.
 - update buildRustPackage's cargoHash/cargoSha256 and cargoSetupHook's cargoDeps
 - update buildGoModule's vendorHash/vendorSha256
 - update buildNpmPackage's npmDepsHash and npmConfigHook's npmDeps
+- update fetchYarnDeps offlineCache output hash
 - update flake outputs (see `--flake`)
 - build and run the resulting package (see `--build`,
   `--run` or `--shell`
diff --git a/nix_update/eval.py b/nix_update/eval.py
index 1503a4e..66e1008 100644
--- a/nix_update/eval.py
+++ b/nix_update/eval.py
@@ -53,6 +53,7 @@ class Package:
     go_modules_old: str | None
     cargo_deps: str | None
     npm_deps: str | None
+    yarn_deps: str | None
     tests: list[str]
     has_update_script: bool
 
@@ -157,6 +158,7 @@ def eval_expression(
     else
       null;
   npm_deps = pkg.npmDeps.outputHash or null;
+  yarn_deps = pkg.offlineCache.outputHash or null;
   tests = builtins.attrNames (pkg.passthru.tests or {{}});
   has_update_script = {has_update_script};
   src_homepage = pkg.src.meta.homepage or null;
diff --git a/nix_update/update.py b/nix_update/update.py
index 41e1dd2..1c80de8 100644
--- a/nix_update/update.py
+++ b/nix_update/update.py
@@ -257,6 +257,11 @@ def update_npm_deps_hash(opts: Options, filename: str, current_hash: str) -> Non
     replace_hash(filename, current_hash, target_hash)
 
 
+def update_yarn_deps_hash(opts: Options, filename: str, current_hash: str) -> None:
+    target_hash = nix_prefetch(opts, "offlineCache")
+    replace_hash(filename, current_hash, target_hash)
+
+
 def update_version(
     package: Package, version: str, preference: VersionPreference, version_regex: str
 ) -> bool:
@@ -362,4 +367,7 @@ def update(opts: Options) -> Package:
         if package.npm_deps:
             update_npm_deps_hash(opts, package.filename, package.npm_deps)
 
+        if package.yarn_deps:
+            update_yarn_deps_hash(opts, package.filename, package.yarn_deps)
+
     return package