diff --git a/pkgs/development/tools/build-managers/buck2/hashes.json b/pkgs/development/tools/build-managers/buck2/hashes.json
index 2ac572b0e46f..2f5bf40356f9 100644
--- a/pkgs/development/tools/build-managers/buck2/hashes.json
+++ b/pkgs/development/tools/build-managers/buck2/hashes.json
@@ -1,4 +1,5 @@
-{ "x86_64-linux": "sha256-xd8MZF1xpVYqEDoL3nUBptiFMn9UkgC+zIgfDkDxwfM="
+{ "_comment": "@generated by pkgs/development/tools/build-managers/buck2/update.sh"
+, "x86_64-linux": "sha256-xd8MZF1xpVYqEDoL3nUBptiFMn9UkgC+zIgfDkDxwfM="
 , "x86_64-darwin": "sha256-d8GD7SwCM1gcWILkmSLRY7nq2w9+AMxgbGiWwAK0BAo="
 , "aarch64-linux": "sha256-zBVgIgQ+tlBUuHwsZB5JmQJtWZ5soKP6//NxkU96xmo="
 , "aarch64-darwin": "sha256-jswrwf37/0Rec551mORXYf+s45Nx16OeaRjRS9ROR4E="
diff --git a/pkgs/development/tools/build-managers/buck2/update.sh b/pkgs/development/tools/build-managers/buck2/update.sh
index f43d2f5517a7..c10774c15ec0 100755
--- a/pkgs/development/tools/build-managers/buck2/update.sh
+++ b/pkgs/development/tools/build-managers/buck2/update.sh
@@ -22,16 +22,13 @@ NFILE=pkgs/development/tools/build-managers/buck2/default.nix
 HFILE=pkgs/development/tools/build-managers/buck2/hashes.json
 rm -f "$HFILE" && touch "$HFILE"
 
-marker="{"
+printf "{ \"_comment\": \"@generated by pkgs/development/tools/build-managers/buck2/update.sh\"\n" >> "$HFILE"
 for arch in "${ARCHS[@]}"; do
     IFS=: read -r arch_name arch_target <<< "$arch"
     sha256hash="$(nix-prefetch-url --type sha256 "https://github.com/facebook/buck2/releases/download/${VERSION}/buck2-${arch_target}.zst")"
     srihash="$(nix hash to-sri --type sha256 "$sha256hash")"
-
-    echo "${marker} \"$arch_name\": \"$srihash\"" >> "$HFILE"
-    marker=","
+    echo ", \"$arch_name\": \"$srihash\"" >> "$HFILE"
 done
-
 echo "}" >> "$HFILE"
 
 sed -i \