diff --git a/src/Finder/MissingKeysFinder.php b/src/Finder/MissingKeysFinder.php
index ea5bac5..3f2a1d6 100644
--- a/src/Finder/MissingKeysFinder.php
+++ b/src/Finder/MissingKeysFinder.php
@@ -56,7 +56,7 @@ protected function extractMissingTranslations(array $foundStrings, array $jsonTr
         foreach ($foundStrings as $string) {
             $string = stripslashes($string);
             if (! array_key_exists($string, $jsonTranslations)) {
-                $missingTranslations[$string] = $string;
+                $missingTranslations[$string] = null;
             }
         }
 
diff --git a/tests/Finder/MissingKeysFinderTest.php b/tests/Finder/MissingKeysFinderTest.php
index 144df74..60d055e 100644
--- a/tests/Finder/MissingKeysFinderTest.php
+++ b/tests/Finder/MissingKeysFinderTest.php
@@ -138,13 +138,13 @@ public function findMissingTranslationsFindsPersistentKeysFromConfig(): void
 
 
     #[Test]
-    public function findMissingTranslatableStringUseKeyAsDefaultValue(): void
+    public function findMissingTranslatableStringUseNullAsDefaultValue(): void
     {
         $multiFunctionFile = $this->createTempFile('multiFunction.php', "<?php echo __('da.key.test'); __('a long string');");
         $translationFinder = new MissingKeysFinder;
 
         $foundStrings = $translationFinder->findMissingTranslatableStrings([$multiFunctionFile], []);
-        $this->assertSame(['da.key.test' => 'da.key.test', 'a long string' => 'a long string'], $foundStrings);
+        $this->assertSame(['da.key.test' => null, 'a long string' => null], $foundStrings);
 
     }
 }
diff --git a/tests/TranslationManagerTest.php b/tests/TranslationManagerTest.php
index 80ca5fe..3876600 100644
--- a/tests/TranslationManagerTest.php
+++ b/tests/TranslationManagerTest.php
@@ -77,9 +77,9 @@ public function translationsAreAppendedWhenNotUsingTranslationService(): void
             $this->jsonFilePath
         );
         $this->assertEquals([
-            'app.title'       => 'app.title',
-            'Something cool ' => 'Something cool ',
-            'greeting'        => 'greeting',
+            'app.title'       => null,
+            'Something cool ' => null,
+            'greeting'        => null,
         ], $missingTranslations);
     }