diff --git a/src/ReadableInterface.php b/src/ReadableInterface.php
index 0f00fb4..cc876af 100644
--- a/src/ReadableInterface.php
+++ b/src/ReadableInterface.php
@@ -9,18 +9,20 @@ interface ReadableInterface
     /**
      * Returns the resource stream of the source.
      *
-     * @return resource returns the streaming contents of a file
-     * @throws SourceExceptionInterface may occur during the inability to
-     *         open or some operations with the resource stream
+     * @return resource Returns the streaming contents of a file.
+     *
+     * @throws SourceExceptionInterface May occur during the inability to
+     *         open or some operations with the resource stream.
      */
     public function getStream();
 
     /**
      * Returns the contents of the source.
      *
-     * @return string returns the string contents of a file
-     * @throws SourceExceptionInterface may occur when it is not possible to
-     *         read source's data and/or convert it to a string
+     * @return string Returns the string contents of a file.
+     *
+     * @throws SourceExceptionInterface May occur when it is not possible to
+     *         read source's data and/or convert it to a string.
      */
     public function getContents(): string;
 
@@ -30,9 +32,10 @@ public function getContents(): string;
      * If the value of the source content changes, the hash value will
      * also be changed.
      *
-     * @return non-empty-string returns hash of a file
-     * @throws SourceExceptionInterface may occur when it is not possible to
-     *         convert object state information into a hash
+     * @return non-empty-string Returns hash of a file.
+     *
+     * @throws SourceExceptionInterface May occur when it is not possible to
+     *         convert object state information into a hash.
      */
     public function getHash(): string;
 }
diff --git a/src/SourceFactoryInterface.php b/src/SourceFactoryInterface.php
index dc71674..3482706 100644
--- a/src/SourceFactoryInterface.php
+++ b/src/SourceFactoryInterface.php
@@ -7,11 +7,11 @@
 interface SourceFactoryInterface
 {
     /**
-     * @param mixed $source arbitrary source reference from which you can
-     *        create a {@see ReadableInterface} instance
+     * @param mixed $source Arbitrary source reference from which you can
+     *        create a {@see ReadableInterface} instance.
      *
-     * @throws SourceExceptionInterface in case of an error in creating the
-     *         source object
+     * @throws SourceExceptionInterface In case of an error in creating the
+     *         source object.
      */
     public function create($source): ReadableInterface;
 }
diff --git a/tests/CompatibilityTest.php b/tests/CompatibilityTest.php
index da70146..b5e9bdb 100644
--- a/tests/CompatibilityTest.php
+++ b/tests/CompatibilityTest.php
@@ -23,9 +23,7 @@ public function testFileCompatibility(): void
             public function getPathname(): string {}
 
             public function getStream() {}
-
             public function getContents(): string {}
-
             public function getHash(): string {}
         };
     }
@@ -41,9 +39,7 @@ public function testFileWithMixedCompatibility(): void
             public function getPathname(): string {}
 
             public function getStream(): mixed {}
-
             public function getContents(): string {}
-
             public function getHash(): string {}
         };
     }
@@ -54,9 +50,7 @@ public function testReadableCompatibility(): void
 
         new class () implements ReadableInterface {
             public function getStream() {}
-
             public function getContents(): string {}
-
             public function getHash(): string {}
         };
     }
@@ -70,9 +64,7 @@ public function testReadableWithMixedCompatibility(): void
 
         new class () implements ReadableInterface {
             public function getStream(): mixed {}
-
             public function getContents(): string {}
-
             public function getHash(): string {}
         };
     }
@@ -90,12 +82,9 @@ public function testSourceFactoryCompatibility(): void
 
         new class () implements SourceFactoryInterface {
             public function create($source): ReadableInterface {}
-
-            public function createFromString(string $content = '', ?string $name = null): ReadableInterface {}
-
+            public function createFromString(string $content = '', string $name = null): ReadableInterface {}
             public function createFromFile(string $filename): FileInterface {}
-
-            public function createFromStream($stream, ?string $name = null): ReadableInterface {}
+            public function createFromStream($stream, string $name = null): ReadableInterface {}
         };
     }
 
@@ -108,12 +97,9 @@ public function testSourceFactoryWithMixedCompatibility(): void
 
         new class () implements SourceFactoryInterface {
             public function create(mixed $source): ReadableInterface {}
-
-            public function createFromString(string $content = '', ?string $name = null): ReadableInterface {}
-
+            public function createFromString(string $content = '', string $name = null): ReadableInterface {}
             public function createFromFile(string $filename): FileInterface {}
-
-            public function createFromStream(mixed $stream, ?string $name = null): ReadableInterface {}
+            public function createFromStream(mixed $stream, string $name = null): ReadableInterface {}
         };
     }
 }