diff --git a/ci/fmt.sh b/ci/fmt.sh
index 31d0c15d..e319a1e4 100755
--- a/ci/fmt.sh
+++ b/ci/fmt.sh
@@ -2,22 +2,24 @@
 set -eu
 cd -- "$(dirname "$0")/.."
 
+# Pin golang.org/x/tools, the go.mod of v0.25.0 is incompatible with Go 1.19.
+X_TOOLS_VERSION=v0.24.0
+
 go mod tidy
 (cd ./internal/thirdparty && go mod tidy)
 (cd ./internal/examples && go mod tidy)
 gofmt -w -s .
-go run golang.org/x/tools/cmd/goimports@latest -w "-local=$(go list -m)" .
+go run golang.org/x/tools/cmd/goimports@${X_TOOLS_VERSION} -w "-local=$(go list -m)" .
 
-npx prettier@3.0.3 \
-  --write \
+git ls-files "*.yml" "*.md" "*.js" "*.css" "*.html" | xargs npx prettier@3.3.3 \
+  --check \
   --log-level=warn \
   --print-width=90 \
   --no-semi \
   --single-quote \
-  --arrow-parens=avoid \
-  $(git ls-files "*.yml" "*.md" "*.js" "*.css" "*.html")
+  --arrow-parens=avoid
 
-go run golang.org/x/tools/cmd/stringer@latest -type=opcode,MessageType,StatusCode -output=stringer.go
+go run golang.org/x/tools/cmd/stringer@${X_TOOLS_VERSION} -type=opcode,MessageType,StatusCode -output=stringer.go
 
 if [ "${CI-}" ]; then
   git diff --exit-code