diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4a212ec..0b453e9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -32,7 +32,7 @@ jobs:
         env:
           COVERALLS_TOKEN: ${{ secrets.github_token }}
       - name: Upload coverage.html
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: coverage
           path: ci/out/coverage.html
diff --git a/ci/fmt.mk b/ci/fmt.mk
index 7f74874..5519ed6 100644
--- a/ci/fmt.mk
+++ b/ci/fmt.mk
@@ -13,7 +13,8 @@ modtidy: gen
 	go mod tidy
 
 gofmt: gen
-	go run mvdan.cc/gofumpt@latest -w .
+	# gofumpt v0.7.0 requires Go 1.22 or later.
+	go run mvdan.cc/gofumpt@v0.6.0 -w .
 
 prettier:
 	npx prettier --write --print-width=120 --no-semi --trailing-comma=all --loglevel=warn $$(git ls-files "*.yml")
diff --git a/ci/lint.mk b/ci/lint.mk
index 36da85b..e190817 100644
--- a/ci/lint.mk
+++ b/ci/lint.mk
@@ -4,4 +4,5 @@ govet:
 	go vet ./...
 
 golint:
-	go run github.com/golangci/golangci-lint/cmd/golangci-lint@latest run .
+	# golangci-lint newer than v1.55.2 is not compatible with Go 1.20 when using go run.
+	go run github.com/golangci/golangci-lint/cmd/golangci-lint@v1.55.2 run .