diff --git a/lib/src/env.dart b/lib/src/env.dart
index d807195..8b219ef 100644
--- a/lib/src/env.dart
+++ b/lib/src/env.dart
@@ -24,8 +24,8 @@ final class Env {
           as T;
     }
 
-    if (currentValue == null && defaultValue != null) {
-      return defaultValue;
+    if (currentValue == null || currentValue is MissingValue && defaultValue != null) {
+      return defaultValue as T;
     }
 
     return currentValue as T;
diff --git a/test/env_guard_test.dart b/test/env_guard_test.dart
index b06bcc6..688ff9e 100644
--- a/test/env_guard_test.dart
+++ b/test/env_guard_test.dart
@@ -7,12 +7,14 @@ final class Env implements DefineEnvironment {
   static final String host = 'HOST';
   static final String port = 'PORT';
   static final String uri = 'URI';
+  static final String optionalKey = 'OPTIONAL_KEY';
 
   @override
   final Map<String, EnvSchema> schema = {
     host: env.string().optional(),
     port: env.number().integer(),
     uri: env.string(),
+    optionalKey: env.string().optional(),
   };
 }
 
@@ -48,7 +50,10 @@ void main() {
         HOST=localhost
       ''');
 
-    env.define(root: directory, {'PORT': env.number().integer(), 'HOST': env.string()});
+    env.define(root: directory, {
+      'PORT': env.number().integer(),
+      'HOST': env.string(),
+    });
 
     expect(env.get('PORT'), 8080);
     expect(env.get('HOST'), 'localhost');
@@ -93,4 +98,14 @@ void main() {
   test('should get null value when environment has not property', () {
     expect(env.get('PORT'), isNull);
   });
+
+  test('should apply defaultValue when environment has not property', () {
+    const attemptValue = "Hello World";
+    expect(env.get('DONT_EXISTS', defaultValue: attemptValue), attemptValue);
+  });
+
+  test('should apply defaultValue when environment has optional property', () {
+    const attemptValue = "Hello World";
+    expect(env.get(Env.optionalKey, defaultValue: attemptValue), attemptValue);
+  });
 }