make UUID regex case-insensitive
diff --git a/format_checkers.go b/format_checkers.go
index c69c4fa..1e77046 100644
--- a/format_checkers.go
+++ b/format_checkers.go
@@ -135,7 +135,7 @@
 	// Use a regex to make sure curly brackets are balanced properly after validating it as a AURI
 	rxURITemplate = regexp.MustCompile("^([^{]*({[^}]*})?)*$")
 
-	rxUUID = regexp.MustCompile("^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$")
+	rxUUID = regexp.MustCompile("^(?i)[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$")
 
 	rxJSONPointer = regexp.MustCompile("^(?:/(?:[^~/]|~0|~1)*)*$")
 
diff --git a/format_checkers_test.go b/format_checkers_test.go
index 65b00ba..6742178 100644
--- a/format_checkers_test.go
+++ b/format_checkers_test.go
@@ -2,8 +2,9 @@
 
 import (
 	"encoding/json"
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestUUIDFormatCheckerIsFormat(t *testing.T) {
@@ -11,6 +12,8 @@
 
 	assert.True(t, checker.IsFormat("01234567-89ab-cdef-0123-456789abcdef"))
 	assert.True(t, checker.IsFormat("f1234567-89ab-cdef-0123-456789abcdef"))
+	assert.True(t, checker.IsFormat("01234567-89AB-CDEF-0123-456789ABCDEF"))
+	assert.True(t, checker.IsFormat("F1234567-89AB-CDEF-0123-456789ABCDEF"))
 
 	assert.False(t, checker.IsFormat("not-a-uuid"))
 	assert.False(t, checker.IsFormat("g1234567-89ab-cdef-0123-456789abcdef"))