diff --git a/pkgs/development/tools/parsing/tree-sitter/update.nix b/pkgs/development/tools/parsing/tree-sitter/update.nix
index 2a3575a44d2..430d2ead026 100644
--- a/pkgs/development/tools/parsing/tree-sitter/update.nix
+++ b/pkgs/development/tools/parsing/tree-sitter/update.nix
@@ -3,11 +3,70 @@
 , src }:
 
 let
-  # print all the grammar names mentioned in the fetch-fixtures script
-  getGrammarNames = writeShellScript "get-grammars.sh" ''
+  # check in the list of grammars, whether we know all of them.
+  checkKnownGrammars = writeShellScript "get-grammars.sh" ''
     set -euo pipefail
-    sed -ne 's/^fetch_grammar \(\S*\).*$/\1/p' \
-      ${src}/script/fetch-fixtures
+    known='
+    [ "tree-sitter-javascript"
+    , "tree-sitter-c"
+    , "tree-sitter-swift"
+    , "tree-sitter-json"
+    , "tree-sitter-cpp"
+    , "tree-sitter-ruby"
+    , "tree-sitter-razor"
+    , "tree-sitter-go"
+    , "tree-sitter-c-sharp"
+    , "tree-sitter-python"
+    , "tree-sitter-typescript"
+    , "tree-sitter-rust"
+    , "tree-sitter-bash"
+    , "tree-sitter-php"
+    , "tree-sitter-java"
+    , "tree-sitter-scala"
+    , "tree-sitter-ocaml"
+    , "tree-sitter-julia"
+    , "tree-sitter-agda"
+    , "tree-sitter-fluent"
+    , "tree-sitter-html"
+    , "tree-sitter-haskell"
+    , "tree-sitter-regex"
+    , "tree-sitter-css"
+    , "tree-sitter-verilog"
+    , "tree-sitter-jsdoc"
+    , "tree-sitter-ql"
+    ]'
+    ignore='
+    [ "tree-sitter"
+    , "tree-sitter-cli"
+    , "tree-sitter-embedded-template"
+    ${/*this is the haskell language bindings, tree-sitter-haskell is the grammar*/""}
+    , "haskell-tree-sitter"
+    ${/*this is the ruby language bindings, tree-sitter-ruby is the grammar*/""}
+    , "ruby-tree-sitter"
+    ${/*this is the (unmaintained) rust language bindings, tree-sitter-rust is the grammar*/""}
+    , "rust-tree-sitter"
+    ${/*this is the nodejs language bindings, tree-sitter-javascript is the grammar*/""}
+    , "node-tree-sitter"
+    ${/*this is the python language bindings, tree-sitter-python is the grammar*/""}
+    , "py-tree-sitter"
+    ${/*afl fuzzing for tree sitter*/""}
+    , "afl-tree-sitter"
+    ${/*archived*/""}
+    , "highlight-schema"
+    ${/*website*/""}
+    , "tree-sitter.github.io"
+    ]'
+    res=$(${jq}/bin/jq \
+      --argjson known "$known" \
+      --argjson ignore "$ignore" \
+      '. - ($known + $ignore)' \
+      )
+    if [ ! "$res" == "[]" ]; then
+      echo "These repositories are neither known nor ignored:" 1>&2
+      echo "$res" 1>&2
+      exit 1
+    fi
+    printf '%s' "$known"
   '';
 
   # TODO
@@ -22,7 +81,7 @@ let
     res=$(${curl}/bin/curl \
       --silent \
       "https://api.github.com/repos/${urlEscape owner}/$(${urlEscapeSh} "$repo")/releases/latest")
-    if [[ "$(printf "%s" "$res" | ${jq}/bin/jq '.message')" =~ "rate limit" ]]; then
+    if [[ "$(printf "%s" "$res" | ${jq}/bin/jq '.message?')" =~ "rate limit" ]]; then
       echo "rate limited" >&2
     fi
     release=$(printf "%s" "$res" | ${jq}/bin/jq '.tag_name')
@@ -34,6 +93,21 @@ let
     echo "$release"
   '';
 
+  # find the latest repos of a github organization
+  latestGithubRepos = { orga }: writeShellScript "latest-github-repos" ''
+    set -euo pipefail
+    res=$(${curl}/bin/curl \
+      --silent \
+      'https://api.github.com/orgs/${orga}/repos?per_page=100')
+
+    if [[ "$(printf "%s" "$res" | ${jq}/bin/jq '.message?')" =~ "rate limit" ]]; then
+      echo "rate limited" >&2
+    fi
+
+    printf "%s" "$res" | ${jq}/bin/jq 'map(.name)' \
+      || echo "failed $res"
+  '';
+
   # update one tree-sitter grammar repo and print their nix-prefetch-git output
   updateGrammar = { owner }: writeShellScript "update-grammar.sh" ''
     set -euo pipefail
@@ -49,18 +123,22 @@ let
 
   update-all-grammars = writeShellScript "update-all-grammars.sh" ''
     set -euo pipefail
-    grammarNames=$(${getGrammarNames})
+    echo "fetching list of grammars" 1>&2
+    grammars=$(${latestGithubRepos { orga = "tree-sitter"; }})
+    echo "checking against the list of grammars we know" 1>&2
+    knownGrammars=$(printf '%s' "$grammars" | ${checkKnownGrammars})
+    # change the json list into a item-per-line bash format
+    grammarNames=$(printf '%s' "$knownGrammars" | ${jq}/bin/jq --raw-output '.[]')
     outputDir="${toString ./.}/grammars"
     mkdir -p "$outputDir"
     updateCommand=$(printf \
       '${updateGrammar { owner = "tree-sitter"; }} "$1" > "%s/$1.json"' \
       "$outputDir")
     printf '%s' "$grammarNames" \
-      | ${xe}/bin/xe printf "tree-sitter-%s\n" {} \
       | ${xe}/bin/xe -j2 -s "$updateCommand"
     ( echo "{"
       printf '%s' "$grammarNames" \
-        | ${xe}/bin/xe -s 'printf "  %s = (builtins.fromJSON (builtins.readFile ./tree-sitter-%s.json));\n" "$1" "$1"'
+        | ${xe}/bin/xe -s 'printf "  %s = (builtins.fromJSON (builtins.readFile ./%s.json));\n" "$1" "$1"'
       echo "}" ) \
       > "$outputDir/default.nix"
   '';