diff --git a/lazy.go b/lazy.go
new file mode 100644
index 00000000..af6cc219
--- /dev/null
+++ b/lazy.go
@@ -0,0 +1,14 @@
+//go:build go1.21
+
+package validator
+
+import (
+	"regexp"
+	"sync"
+)
+
+func lazyRegexCompile(str string) func() *regexp.Regexp {
+	return sync.OnceValue(func() *regexp.Regexp {
+		return regexp.MustCompile(str)
+	})
+}
diff --git a/lazy_compat.go b/lazy_compat.go
new file mode 100644
index 00000000..5270f021
--- /dev/null
+++ b/lazy_compat.go
@@ -0,0 +1,46 @@
+//go:build !go1.21
+
+package validator
+
+import (
+	"regexp"
+	"sync"
+)
+
+// Copied and adapted from go1.21 stdlib's sync.OnceValue for backwards compatibility:
+// OnceValue returns a function that invokes f only once and returns the value
+// returned by f. The returned function may be called concurrently.
+//
+// If f panics, the returned function will panic with the same value on every call.
+func onceValue(f func() *regexp.Regexp) func() *regexp.Regexp {
+	var (
+		once   sync.Once
+		valid  bool
+		p      any
+		result *regexp.Regexp
+	)
+	g := func() {
+		defer func() {
+			p = recover()
+			if !valid {
+				panic(p)
+			}
+		}()
+		result = f()
+		f = nil
+		valid = true
+	}
+	return func() *regexp.Regexp {
+		once.Do(g)
+		if !valid {
+			panic(p)
+		}
+		return result
+	}
+}
+
+func lazyRegexCompile(str string) func() *regexp.Regexp {
+	return onceValue(func() *regexp.Regexp {
+		return regexp.MustCompile(str)
+	})
+}
diff --git a/regexes.go b/regexes.go
index f0dc2581..df0cfde7 100644
--- a/regexes.go
+++ b/regexes.go
@@ -1,10 +1,5 @@
 package validator
 
-import (
-	"regexp"
-	"sync"
-)
-
 const (
 	alphaRegexString                 = "^[a-zA-Z]+$"
 	alphaNumericRegexString          = "^[a-zA-Z0-9]+$"
@@ -79,12 +74,6 @@ const (
 	spicedbTypeRegexString           = "^([a-z][a-z0-9_]{1,61}[a-z0-9]/)?[a-z][a-z0-9_]{1,62}[a-z0-9]$"
 )
 
-func lazyRegexCompile(str string) func() *regexp.Regexp {
-	return sync.OnceValue(func() *regexp.Regexp {
-		return regexp.MustCompile(str)
-	})
-}
-
 var (
 	alphaRegex                 = lazyRegexCompile(alphaRegexString)
 	alphaNumericRegex          = lazyRegexCompile(alphaNumericRegexString)