diff --git a/docs/release-notes.md b/docs/release-notes.md
index 95d3ad5a66..84cc7b7be6 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -12,6 +12,8 @@ nav_order: 9
 
 ### Changes
 
+- `./test` validates the Butane configs in `butane/docs`, restoring coverage that was lost when Butane merged into this repository
+
 ### Bug fixes
 
 - Resolve intermediate symlinks in relabel paths, fixing SELinux relabeling failures for users with `home_dir` on OSTree platforms after policycoreutils 3.11 ([#2316](https://github.com/coreos/ignition/pull/2316))
diff --git a/internal/util/tools/docs/docs.go b/internal/util/tools/docs/docs.go
index 11731ada7c..ccc09e3a42 100644
--- a/internal/util/tools/docs/docs.go
+++ b/internal/util/tools/docs/docs.go
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 // Reads all markdown files in the specified directory and validates the
-// Ignition configs wrapped in code fences.
+// Ignition and Butane configs wrapped in code fences.
 
 package main
 
@@ -24,18 +24,50 @@ import (
 	"path/filepath"
 	"strings"
 
-	"github.com/coreos/ignition/v2/config"
+	butane "github.com/coreos/ignition/v2/butane/config"
+	butanecommon "github.com/coreos/ignition/v2/butane/config/common"
+	ignition "github.com/coreos/ignition/v2/config"
 )
 
-// Specific section marker used in the docs to indicate that the Markdown code
-// section right after it should be treated as being a valid Ignition config
-// and thus used for testing.
+// Specific section markers used in the docs to indicate that the Markdown code
+// section right after one should be treated as being a valid config and thus
+// used for testing.
 const (
-	sectionMarker = "<!-- ignition -->"
+	ignitionMarker = "<!-- ignition -->"
+	butaneMarker   = "<!-- butane-config -->"
 )
 
-// Represent the state we are in while trying to extract Ignition config
-// sections from the examples in the docs.
+// The kind of config a section holds, which determines both the code fence it
+// must use and how it is validated.
+type configKind int
+
+const (
+	ignitionConfig configKind = iota
+	butaneConfig
+)
+
+func (k configKind) fence() string {
+	if k == butaneConfig {
+		return "```yaml"
+	}
+	return "```json"
+}
+
+func (k configKind) String() string {
+	if k == butaneConfig {
+		return "Butane"
+	}
+	return "Ignition"
+}
+
+// A config section extracted from a Markdown file.
+type configSection struct {
+	kind  configKind
+	lines []string
+}
+
+// Represent the state we are in while trying to extract config sections from
+// the examples in the docs.
 type sectionState int
 
 const (
@@ -46,12 +78,14 @@ const (
 
 func main() {
 	flags := struct {
-		help bool
-		root string
+		help     bool
+		root     string
+		filesDir string
 	}{}
 
 	flag.BoolVar(&flags.help, "help", false, "Print help and exit.")
 	flag.StringVar(&flags.root, "root", "docs", "Path to the documentation.")
+	flag.StringVar(&flags.filesDir, "files-dir", "", "Directory Butane configs may embed local files from.")
 
 	flag.Parse()
 
@@ -75,28 +109,20 @@ func main() {
 		}
 
 		fileLines := strings.Split(string(fileContents), "\n")
-		jsonSections, ignored, err := findJsonSections(fileLines)
+		sections, ignored, err := findConfigSections(fileLines)
 		if err != nil {
 			return fmt.Errorf("invalid section formatting in %s: %s", path, err)
 		}
-		if len(jsonSections) != 0 {
-			fmt.Printf("Found %d sections in: %s\n", len(jsonSections), path)
+		if len(sections) != 0 {
+			fmt.Printf("Found %d sections in: %s\n", len(sections), path)
 		}
 		if ignored != 0 {
 			fmt.Printf("Ignored %d partial or empty sections in: %s\n", ignored, path)
 		}
 
-		for _, json := range jsonSections {
-			cfg := strings.Join(json, "\n")
-			_, r, err := config.Parse([]byte(cfg))
-			// the report provides a more specific error
-			// description, so check that first
-			reportStr := r.String()
-			if reportStr != "" {
-				return fmt.Errorf("non-empty parsing report in %s: %s\nConfig:\n%s", info.Name(), reportStr, cfg)
-			}
-			if err != nil {
-				return fmt.Errorf("fatal error parsing %s: %s\nConfig:\n%s", info.Name(), err, cfg)
+		for _, section := range sections {
+			if err := validateSection(section, info.Name(), flags.filesDir); err != nil {
+				return err
 			}
 		}
 
@@ -107,9 +133,45 @@ func main() {
 	}
 }
 
-func findJsonSections(fileLines []string) ([][]string, uint, error) {
-	var jsonSections [][]string
+// validateSection checks one config section, matching the strictness of
+// `ignition-validate` and of `butane --check --strict` respectively.
+func validateSection(section configSection, name, filesDir string) error {
+	cfg := strings.Join(section.lines, "\n")
+
+	switch section.kind {
+	case butaneConfig:
+		_, r, err := butane.TranslateBytes([]byte(cfg), butanecommon.TranslateBytesOptions{
+			TranslateOptions: butanecommon.TranslateOptions{
+				FilesDir: filesDir,
+			},
+		})
+		if err != nil {
+			return fmt.Errorf("fatal error translating %s: %s\nConfig:\n%s", name, err, cfg)
+		}
+		// `--strict` treats any report entry, warnings included, as fatal
+		if len(r.Entries) > 0 {
+			return fmt.Errorf("non-empty translation report in %s: %s\nConfig:\n%s", name, r.String(), cfg)
+		}
+	default:
+		_, r, err := ignition.Parse([]byte(cfg))
+		// the report provides a more specific error
+		// description, so check that first
+		reportStr := r.String()
+		if reportStr != "" {
+			return fmt.Errorf("non-empty parsing report in %s: %s\nConfig:\n%s", name, reportStr, cfg)
+		}
+		if err != nil {
+			return fmt.Errorf("fatal error parsing %s: %s\nConfig:\n%s", name, err, cfg)
+		}
+	}
+
+	return nil
+}
+
+func findConfigSections(fileLines []string) ([]configSection, uint, error) {
+	var sections []configSection
 	var currentSection []string
+	var currentKind configKind
 
 	var ignoredSections uint = 0
 	var state = notInSection
@@ -117,15 +179,20 @@ func findJsonSections(fileLines []string) ([][]string, uint, error) {
 	for _, line := range fileLines {
 		switch state {
 		case notInSection:
-			if line == sectionMarker {
+			switch line {
+			case ignitionMarker:
+				currentKind = ignitionConfig
+				state = expectingSection
+			case butaneMarker:
+				currentKind = butaneConfig
 				state = expectingSection
 			}
 
 		case expectingSection:
-			if line == "```json" {
+			if line == currentKind.fence() {
 				state = inSection
 			} else {
-				return jsonSections, ignoredSections, fmt.Errorf("expecting '```json', found: %s", line)
+				return sections, ignoredSections, fmt.Errorf("expecting '%s', found: %s", currentKind.fence(), line)
 			}
 
 		case inSection:
@@ -134,7 +201,10 @@ func findJsonSections(fileLines []string) ([][]string, uint, error) {
 					// Ignore empty sections and sections that are not full configs
 					ignoredSections++
 				} else {
-					jsonSections = append(jsonSections, currentSection)
+					sections = append(sections, configSection{
+						kind:  currentKind,
+						lines: currentSection,
+					})
 				}
 				currentSection = nil
 				state = notInSection
@@ -143,5 +213,15 @@ func findJsonSections(fileLines []string) ([][]string, uint, error) {
 			}
 		}
 	}
-	return jsonSections, ignoredSections, nil
+
+	// A file ending mid-section would otherwise drop that section and report
+	// success, silently skipping validation of it.
+	switch state {
+	case expectingSection:
+		return sections, ignoredSections, fmt.Errorf("expecting '%s' after %s marker, found end of file", currentKind.fence(), currentKind)
+	case inSection:
+		return sections, ignoredSections, fmt.Errorf("unterminated %s config section", currentKind)
+	}
+
+	return sections, ignoredSections, nil
 }
diff --git a/test b/test
index 1fe2a233fe..a4312e5851 100755
--- a/test
+++ b/test
@@ -75,6 +75,18 @@ fi
 
 echo "Checking docs..."
 go run internal/util/tools/docs/docs.go
+
+echo "Checking Butane docs..."
+# Butane configs in the docs embed local files; supply the ones they reference
+# so translation fails on a broken config rather than on a missing file.
+butane_files_dir=$(mktemp -d)
+trap 'rm -rf "${butane_files_dir}"' EXIT
+mkdir -p "${butane_files_dir}/tree"
+touch "${butane_files_dir}"/{config.ign,ca.pem,example.conf,example.service,file,file-epilogue,local-file3}
+echo "ssh-rsa AAAA" > "${butane_files_dir}/id_rsa.pub"
+echo "ssh-ed25519 AAAA" > "${butane_files_dir}/id_ed25519.pub"
+echo '{"ignition": {"version": "3.5.0"}}' > "${butane_files_dir}/ignition.ign"
+go run internal/util/tools/docs/docs.go -root butane/docs -files-dir "${butane_files_dir}"
 # Ensure every platform is listed in supported-platforms.md
 platforms=$(grep -A 1 -h platform.Register internal/providers/*/* | grep Name: | cut -f2 -d\")
 if [ -z "${platforms}" ]; then
@@ -101,7 +113,7 @@ if [ ! -x "${BUTANE_BIN}" ]; then
 fi
 shopt -s nullglob
 tmpdir=$(mktemp -d)
-trap 'rm -rf "${tmpdir}"' EXIT
+trap 'rm -rf "${butane_files_dir}" "${tmpdir}"' EXIT
 # Create files-dir contents expected by example configs
 mkdir -p "${tmpdir}/files-dir/tree"
 touch "${tmpdir}/files-dir/"{config.ign,ca.pem,example.conf,example.service,file,file-epilogue,local-file3}