diff --git a/pkg/parser/parser.go b/pkg/parser/parser.go
index d307ff55..53259895 100644
--- a/pkg/parser/parser.go
+++ b/pkg/parser/parser.go
@@ -19,8 +19,6 @@ package parser
 import (
 	"fmt"
 	"strings"
-
-	specs "tags.cncf.io/container-device-interface/specs-go"
 )
 
 // QualifiedName returns the qualified name for a device.
@@ -107,7 +105,11 @@ func ParseDevice(device string) (string, string, string) {
 // If parsing fails, an empty vendor and the class set to the
 // verbatim input is returned.
 func ParseQualifier(kind string) (string, string) {
-	return specs.ParseQualifier(kind)
+	parts := strings.SplitN(kind, "/", 2)
+	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+		return "", kind
+	}
+	return parts[0], parts[1]
 }
 
 // ValidateVendorName checks the validity of a vendor name.
@@ -196,7 +198,7 @@ func ValidateDeviceName(name string) error {
 
 // IsLetter reports whether the rune is a letter.
 func IsLetter(c rune) bool {
-	return specs.IsLetter(c)
+	return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z')
 }
 
 // IsDigit reports whether the rune is a digit.
diff --git a/specs-go/parser.go b/specs-go/parser.go
index 7bdf0ea4..f6c07da4 100644
--- a/specs-go/parser.go
+++ b/specs-go/parser.go
@@ -18,14 +18,14 @@ package specs
 
 import "strings"
 
-// ParseQualifier splits a device qualifier into vendor and class.
+// parseQualifier splits a device qualifier into vendor and class.
 // The syntax for a device qualifier is
 //
 //	"<vendor>/<class>"
 //
 // If parsing fails, an empty vendor and the class set to the
 // verbatim input is returned.
-func ParseQualifier(kind string) (string, string) {
+func parseQualifier(kind string) (string, string) {
 	parts := strings.SplitN(kind, "/", 2)
 	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
 		return "", kind
@@ -33,7 +33,7 @@ func ParseQualifier(kind string) (string, string) {
 	return parts[0], parts[1]
 }
 
-// IsLetter reports whether the rune is a letter.
-func IsLetter(c rune) bool {
+// isLetter reports whether the rune is an ASCII letter.
+func isLetter(c rune) bool {
 	return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z')
 }
diff --git a/specs-go/version.go b/specs-go/version.go
index 9feebca7..cd5dcaaa 100644
--- a/specs-go/version.go
+++ b/specs-go/version.go
@@ -70,7 +70,7 @@ func ValidateVersion(spec *Spec) error {
 	if err != nil {
 		return fmt.Errorf("could not determine minimum required version: %w", err)
 	}
-	if newVersion(minVersion).IsGreaterThan(newVersion(spec.Version)) {
+	if newVersion(minVersion).isGreaterThan(newVersion(spec.Version)) {
 		return fmt.Errorf("the spec version must be at least v%v", minVersion)
 	}
 	return nil
@@ -97,12 +97,12 @@ func (v version) String() string {
 }
 
 // IsGreaterThan checks with a version is greater than the specified version.
-func (v version) IsGreaterThan(o version) bool {
+func (v version) isGreaterThan(o version) bool {
 	return semver.Compare(string(v), string(o)) > 0
 }
 
 // IsLatest checks whether the version is the latest supported version
-func (v version) IsLatest() bool {
+func (v version) isLatest() bool {
 	return v == vCurrent
 }
 
@@ -126,11 +126,11 @@ func (r requiredVersionMap) requiredVersion(spec *Spec) version {
 		if isRequired == nil {
 			continue
 		}
-		if isRequired(spec) && v.IsGreaterThan(minVersion) {
+		if isRequired(spec) && v.isGreaterThan(minVersion) {
 			minVersion = v
 		}
 		// If we have already detected the latest version then no later version could be detected
-		if minVersion.IsLatest() {
+		if minVersion.isLatest() {
 			break
 		}
 	}
@@ -183,7 +183,7 @@ func requiresV060(spec *Spec) bool {
 	}
 
 	// The v0.6.0 spec allows dots "." in Kind name label (class)
-	vendor, class := ParseQualifier(spec.Kind)
+	vendor, class := parseQualifier(spec.Kind)
 	if vendor != "" {
 		if strings.ContainsRune(class, '.') {
 			return true
@@ -199,7 +199,7 @@ func requiresV050(spec *Spec) bool {
 
 	for _, d := range spec.Devices {
 		// The v0.5.0 spec allowed device names to start with a digit instead of requiring a letter
-		if len(d.Name) > 0 && !IsLetter(rune(d.Name[0])) {
+		if len(d.Name) > 0 && !isLetter(rune(d.Name[0])) {
 			return true
 		}
 		edits = append(edits, &d.ContainerEdits)