diff --git a/stringutil/stringutil.go b/stringutil/stringutil.go
deleted file mode 100644
index aedb198..0000000
--- a/stringutil/stringutil.go
+++ /dev/null
@@ -1,21 +0,0 @@
-package stringutil
-
-// Map applies f to each string in in.
-func Map(in []string, f func(string) string) []string {
-	res := make([]string, 0, len(in))
-	for _, s := range in {
-		res = append(res, f(s))
-	}
-	return res
-}
-
-// Contains returns true if in contains element,
-// false if not.
-func Contains(in []string, element string) bool {
-	for _, a := range in {
-		if a == element {
-			return true
-		}
-	}
-	return false
-}
diff --git a/stringutil/stringutil_test.go b/stringutil/stringutil_test.go
deleted file mode 100644
index 61ab494..0000000
--- a/stringutil/stringutil_test.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package stringutil_test
-
-import (
-	"github.com/lithictech/go-aperitif/stringutil"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-	"strings"
-	"testing"
-)
-
-func TestStringUtil(t *testing.T) {
-	RegisterFailHandler(Fail)
-	RunSpecs(t, "stringutil Suite")
-}
-
-var _ = Describe("Map", func() {
-	It("maps the input slice", func() {
-		s := []string{"a", "b"}
-		res := stringutil.Map(s, strings.ToUpper)
-		Expect(res).To(Equal([]string{"A", "B"}))
-	})
-})
-
-var _ = Describe("Contains", func() {
-	It("is true if the slice contains the string", func() {
-		s := []string{"a", "b"}
-		Expect(stringutil.Contains(s, "a")).To(BeTrue())
-		Expect(stringutil.Contains(s, "A")).To(BeFalse())
-	})
-})
diff --git a/validator/stringutil.go b/validator/stringutil.go
new file mode 100644
index 0000000..8ea7f8f
--- /dev/null
+++ b/validator/stringutil.go
@@ -0,0 +1,18 @@
+package validator
+
+func mapString(in []string, f func(string) string) []string {
+	res := make([]string, 0, len(in))
+	for _, s := range in {
+		res = append(res, f(s))
+	}
+	return res
+}
+
+func containsString(in []string, element string) bool {
+	for _, a := range in {
+		if a == element {
+			return true
+		}
+	}
+	return false
+}
diff --git a/validator/validators.go b/validator/validators.go
index 223ac2b..357a36b 100644
--- a/validator/validators.go
+++ b/validator/validators.go
@@ -3,7 +3,6 @@ package validator
 import (
 	"errors"
 	"github.com/lithictech/go-aperitif/kronos"
-	"github.com/lithictech/go-aperitif/stringutil"
 	"github.com/rgalanakis/validator"
 	"net/url"
 	"regexp"
@@ -92,7 +91,7 @@ func validateEnumImpl(v interface{}, param string, mapper func(string) string) e
 		return err
 	}
 	if mapper != nil {
-		choices = stringutil.Map(choices, mapper)
+		choices = mapString(choices, mapper)
 	}
 
 	if s, ok := v.(string); ok {
@@ -110,7 +109,7 @@ func validateEnumImpl(v interface{}, param string, mapper func(string) string) e
 			return validator.ErrBadParameter
 		}
 		if mapper != nil {
-			ss = stringutil.Map(ss, mapper)
+			ss = mapString(ss, mapper)
 		}
 		return validateEnumImplSlice(ss, choices)
 	}
@@ -139,7 +138,7 @@ func validateEnumImplStr(s string, choices []string, optional bool) error {
 
 func validateEnumImplSlice(ss []string, choices []string) error {
 	for _, s := range ss {
-		if !stringutil.Contains(choices, s) {
+		if !containsString(choices, s) {
 			return newError("element not one of " + strings.Join(choices, "|"))
 		}
 	}