diff --git a/common/pkgs/mastodon/source.nix b/common/pkgs/mastodon/source.nix
index ba46188..bbd0c01 100644
--- a/common/pkgs/mastodon/source.nix
+++ b/common/pkgs/mastodon/source.nix
@@ -1,5 +1,6 @@
 # This file was generated by pkgs.mastodon.updateScript.
-{ fetchFromGitHub, applyPatches, patches ? [ ] }:
+{ lib, fetchFromGitHub, applyPatches, postPatch ? "", patches ? [ ], gawk
+, gnused, yarn-berry }:
 let version = "f571dbe35dbc4876f9ca76b3f6d459839c67a2ef";
 in (applyPatches {
   src = fetchFromGitHub {
@@ -8,8 +9,19 @@ in (applyPatches {
     rev = "${version}";
     sha256 = "3ZJMiciV0muv5j468hEKJUZGDhKcNCJnDFn6ZqKM1F4=";
   };
-  patches = patches ++ [ ./yarn-typescript.patch ];
+  inherit patches;
+
+  nativeBuildInputs = [ gawk gnused ];
+  postPatch = postPatch
+    + lib.optionalString (lib.versionAtLeast yarn-berry.version "4.1.0") ''
+      # this is for yarn starting with 4.1.0 because fuck everything amirite
+      # see also https://github.com/yarnpkg/berry/pull/6083
+      echo "patching cachekey in yarn.lock"
+      cacheKey="$(awk -e '/cacheKey:/ {print $2}' yarn.lock)"
+      sed -i -Ee 's|^  checksum: ([^/]*)$|  checksum: '$cacheKey'/\1|g;' yarn.lock
+    '';
+
 }) // {
   inherit version;
-  yarnHash = "sha256-qE1TBqa3BSEu1MC3Qw/k3h7QEicWd3AwJdA+U1v8924=";
+  yarnHash = "sha256-wdEunwUsV/IaJvNq+YIqRXNKLBrqPeeL5Ig+33dT/AY=";
 }
diff --git a/common/pkgs/mastodon/update.sh b/common/pkgs/mastodon/update.sh
index ff8d4ac..45733d4 100755
--- a/common/pkgs/mastodon/update.sh
+++ b/common/pkgs/mastodon/update.sh
@@ -66,7 +66,7 @@ trap cleanup EXIT
 
 echo "Fetching source code $REVISION"
 JSON=$(nix-prefetch-github "$OWNER" "$REPO" --rev "$REVISION" 2> $WORK_DIR/nix-prefetch-git.out)
-HASH=$(echo "$JSON" | jq -r .hash)
+HASH=$(echo "$JSON" | jq -r .sha256)
 
 cat > source.nix << EOF
 # This file was generated by pkgs.mastodon.updateScript.
@@ -80,7 +80,7 @@ in
       owner = "$OWNER";
       repo = "$REPO";
       rev = "\${version}";
-      hash = "$HASH";
+      sha256 = "$HASH";
     };
     patches = patches ++ [$PATCHES];
   }) // {
@@ -94,7 +94,8 @@ echo "Creating gemset.nix"
 bundix --lockfile="$SOURCE_DIR/Gemfile.lock" --gemfile="$SOURCE_DIR/Gemfile"
 echo "" >> gemset.nix  # Create trailing newline to please EditorConfig checks
 
-echo "Creating yarn-hash.nix"
-YARN_HASH="$(prefetch-yarn-deps "$SOURCE_DIR/yarn.lock")"
-YARN_HASH="$(nix hash to-sri --type sha256 "$YARN_HASH")"
-sed -i "s/sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=/$YARN_HASH/g" source.nix
+# echo "Creating yarn-hash.nix"
+# YARN_HASH="$(prefetch-yarn-deps "$SOURCE_DIR/yarn.lock")"
+# YARN_HASH="$(nix hash to-sri --type sha256 "$YARN_HASH")"
+# sed -i "s/sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=/$YARN_HASH/g" source.nix
+sed -i -Ee "s|^( *yarnHash = )\".*\";|\\1\"\";|g;" ./source.nix
diff --git a/common/pkgs/mastodon/yarn-typescript.patch b/common/pkgs/mastodon/yarn-typescript.patch
deleted file mode 100644
index e0f90bf..0000000
--- a/common/pkgs/mastodon/yarn-typescript.patch
+++ /dev/null
@@ -1,15 +0,0 @@
---- a/yarn.lock
-+++ b/yarn.lock
-@@ -16483,11 +16483,11 @@
-
- "typescript@patch:typescript@npm%3A5#optional!builtin<compat/typescript>, typescript@patch:typescript@npm%3A^5.0.4#optional!builtin<compat/typescript>":
-   version: 5.3.3
--  resolution: "typescript@patch:typescript@npm%3A5.3.3#optional!builtin<compat/typescript>::version=5.3.3&hash=e012d7"
-+  resolution: "typescript@patch:typescript@npm%3A5.3.3#optional!builtin<compat/typescript>::version=5.3.3&hash=29ae49"
-   bin:
-     tsc: bin/tsc
-     tsserver: bin/tsserver
--  checksum: 1d0a5f4ce496c42caa9a30e659c467c5686eae15d54b027ee7866744952547f1be1262f2d40de911618c242b510029d51d43ff605dba8fb740ec85ca2d3f9500
-+  checksum: e22df47df9b2b2f2617b8bf511a29aea3d177f9f7a0756818230a76b01cbd7da988bf55f9463aaa1a4c1ff90b80f8dc5676460d4e9dfc010572cbba59b822b0c
-   languageName: node
-   linkType: hard
diff --git a/common/pkgs/mastodon/yarn.nix b/common/pkgs/mastodon/yarn.nix
index bdde07d..a1c63f4 100644
--- a/common/pkgs/mastodon/yarn.nix
+++ b/common/pkgs/mastodon/yarn.nix
@@ -20,7 +20,14 @@ stdenvNoCC.mkDerivation {
     export YARN_COMPRESSION_LEVEL=0
 
     cache="$(yarn config get cacheFolder)"
-    yarn install --immutable --mode skip-build
+    if ! yarn install --immutable --mode skip-build; then
+      cp yarn.lock yarn.lock.bak
+      yarn install --mode skip-build
+      diff -u yarn.lock.bak yarn.lock
+      echo "yarn build failed! diff generated as yarn.lock.diff"
+      pwd
+      exit 1
+    fi
 
     cp -r $cache/* $out/
   '';