diff --git a/lib/src/guid.dart b/lib/src/guid.dart
index 640c88c..ac001f5 100644
--- a/lib/src/guid.dart
+++ b/lib/src/guid.dart
@@ -5,6 +5,6 @@ class Guid {
 
   final RandomGenerator random;
 
-  String? guid() =>
+  String guid() =>
       random.fromPatternToHex(['########-####-####-####-############']);
 }
diff --git a/lib/src/phone_number.dart b/lib/src/phone_number.dart
index 0cd5ac3..e81d087 100644
--- a/lib/src/phone_number.dart
+++ b/lib/src/phone_number.dart
@@ -41,5 +41,5 @@ class PhoneNumber {
 
   final RandomGenerator random;
 
-  String? us() => random.fromPattern(usPhoneNumberPatterns);
+  String us() => random.fromPattern(usPhoneNumberPatterns);
 }