diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfa31f9..35555b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,8 @@ CHANGELOG
   become `gmail.com`.
 * Additional `gmail.com` typos are now normalized when `hashEmail` is used.
   For example, `gmali.com` will become `gmail.com`.
+* When `hashEmail` is used, the local part of an email address is now
+  normalized to NFC.
 
 2.0.0 (2023-12-04)
 ------------------
diff --git a/composer.json b/composer.json
index 111768a..1e22117 100644
--- a/composer.json
+++ b/composer.json
@@ -29,6 +29,9 @@
     "squizlabs/php_codesniffer": "*",
     "phpstan/phpstan": "*"
   },
+  "suggest": {
+    "ext-intl": "Enables improved email address IDN normalization"
+  },
   "autoload": {
     "psr-4": {
       "MaxMind\\": "src"
diff --git a/src/MinFraud/Util.php b/src/MinFraud/Util.php
index e95c796..ce0ff5d 100644
--- a/src/MinFraud/Util.php
+++ b/src/MinFraud/Util.php
@@ -297,6 +297,10 @@ public static function maybeHashEmail(array $values): array
         $domain = self::cleanDomain(substr($address, $atIdx + 1));
         $localPart = substr($address, 0, $atIdx);
 
+        if (class_exists('Normalizer')) {
+            $localPart = \Normalizer::normalize($localPart, \Normalizer::FORM_C);
+        }
+
         if ($domain !== '' && !isset($values['email']['domain'])) {
             $values['email']['domain'] = $domain;
         }
diff --git a/tests/MaxMind/Test/MinFraud/UtilTest.php b/tests/MaxMind/Test/MinFraud/UtilTest.php
index b547463..56e8d6b 100644
--- a/tests/MaxMind/Test/MinFraud/UtilTest.php
+++ b/tests/MaxMind/Test/MinFraud/UtilTest.php
@@ -308,6 +308,46 @@ public function testMaybeHashEmail(): void
                         ],
                     ],
                 ],
+                [
+                    'name' => 'email domain nfc normalization form 1',
+                    'input' => ['email' => ['address' => "example@bu\u{0308}cher.com"]],
+                    'expected' => [
+                        'email' => [
+                            'address' => '2b21bc76dab3c8b1622837c1d698936c',
+                            'domain' => 'xn--bcher-kva.com',
+                        ],
+                    ],
+                ],
+                [
+                    'name' => 'email domain nfc normalization form 2',
+                    'input' => ['email' => ['address' => "example@b\u{00FC}cher.com"]],
+                    'expected' => [
+                        'email' => [
+                            'address' => '2b21bc76dab3c8b1622837c1d698936c',
+                            'domain' => 'xn--bcher-kva.com',
+                        ],
+                    ],
+                ],
+                [
+                    'name' => 'email local part nfc normalization form 1',
+                    'input' => ['email' => ['address' => "bu\u{0308}cher@example.com"]],
+                    'expected' => [
+                        'email' => [
+                            'address' => '53550c712b146287a2d0dd30e5ed6f4b',
+                            'domain' => 'example.com',
+                        ],
+                    ],
+                ],
+                [
+                    'name' => 'email local part nfc normalization form 2',
+                    'input' => ['email' => ['address' => "b\u{00FC}cher@example.com"]],
+                    'expected' => [
+                        'email' => [
+                            'address' => '53550c712b146287a2d0dd30e5ed6f4b',
+                            'domain' => 'example.com',
+                        ],
+                    ],
+                ],
             );
         }