diff --git a/src/Message.php b/src/Message.php
index 40d13143..f1959daa 100644
--- a/src/Message.php
+++ b/src/Message.php
@@ -310,15 +310,15 @@ public function isMime()
      * $stringOrHandle is expected to be in UTF-8 regardless of the target
      * charset.
      *
-     * @param string|resource $stringOrHandle
+     * @param string|resource|StreamInterface $resource
      * @param string $charset
      */
-    public function setTextPart($stringOrHandle, $charset = 'UTF-8')
+    public function setTextPart($resource, $charset = 'UTF-8')
     {
         $this->messageHelperService
             ->getMultipartHelper()
             ->setContentPartForMimeType(
-                $this, 'text/plain', $stringOrHandle, $charset
+                $this, 'text/plain', $resource, $charset
             );
     }
 
@@ -331,15 +331,15 @@ public function setTextPart($stringOrHandle, $charset = 'UTF-8')
      * $stringOrHandle is expected to be in UTF-8 regardless of the target
      * charset.
      *
-     * @param string|resource $stringOrHandle
+     * @param string|resource|StreamInterface $resource
      * @param string $charset
      */
-    public function setHtmlPart($stringOrHandle, $charset = 'UTF-8')
+    public function setHtmlPart($resource, $charset = 'UTF-8')
     {
         $this->messageHelperService
             ->getMultipartHelper()
             ->setContentPartForMimeType(
-                $this, 'text/html', $stringOrHandle, $charset
+                $this, 'text/html', $resource, $charset
             );
     }
 
@@ -462,8 +462,7 @@ public function addAttachmentPartFromFile($file, $mimeType, $filename = null, $d
      * Returns a string containing the entire body of a signed message for
      * verification or calculating a signature.
      *
-     * @return string or null if the message doesn't have any children, or the
-     *      child returns null for getHandle
+     * @return string or null if the message doesn't have any children
      */
     public function getSignedMessageAsString()
     {
diff --git a/src/Message/Part/MessagePart.php b/src/Message/Part/MessagePart.php
index 420182a4..c72d6338 100644
--- a/src/Message/Part/MessagePart.php
+++ b/src/Message/Part/MessagePart.php
@@ -202,7 +202,7 @@ public abstract function isMime();
      * 
      * @return resource the resource handle
      */
-    public function getHandle()
+    public function getResourceHandle()
     {
         return StreamWrapper::getResource($this->getStream());
     }
@@ -364,14 +364,14 @@ public function detachContentStream()
     }
 
     /**
-     * Sets the content of the part to the passed string.
+     * Sets the content of the part to the passed resource.
      *
-     * @param string|resource $stringOrHandle
+     * @param string|resource|StreamInterface $resource
      * @param string $charset
      */
-    public function setContent($stringOrHandle, $charset = MailMimeParser::DEFAULT_CHARSET)
+    public function setContent($resource, $charset = MailMimeParser::DEFAULT_CHARSET)
     {
-        $stream = Psr7\stream_for($stringOrHandle);
+        $stream = Psr7\stream_for($resource);
         $this->attachContentStream($stream, $charset);
         // this->onChange called in attachContentStream
     }
@@ -385,12 +385,10 @@ public function save($streamOrHandle)
     {
         $message = $this->getStream();
         $message->rewind();
-        if (!($streamOrHandle instanceof StreamInterface)) {
-            $streamOrHandle = Psr7\stream_for($streamOrHandle);
-        }
-        Psr7\copy_to_stream($message, $streamOrHandle);
+        $stream = Psr7\stream_for($streamOrHandle);
+        Psr7\copy_to_stream($message, $stream);
         // don't close when out of scope
-        $streamOrHandle->detach();
+        $stream->detach();
     }
 
     /**
diff --git a/tests/MailMimeParser/Message/Part/MessagePartTest.php b/tests/MailMimeParser/Message/Part/MessagePartTest.php
index f9c98e6b..d5dcba0f 100644
--- a/tests/MailMimeParser/Message/Part/MessagePartTest.php
+++ b/tests/MailMimeParser/Message/Part/MessagePartTest.php
@@ -56,7 +56,7 @@ public function testNewInstance()
         $this->assertNull($messagePart->getContentResourceHandle());
         $this->assertNull($messagePart->getContent());
         $this->assertNull($messagePart->getParent());
-        $this->assertEquals('habibi', stream_get_contents($messagePart->getHandle()));
+        $this->assertEquals('habibi', stream_get_contents($messagePart->getResourceHandle()));
     }
     
     public function testPartStreamHandle()
@@ -64,8 +64,8 @@ public function testPartStreamHandle()
         $messagePart = $this->getMessagePart('mucha agua');
         $this->assertFalse($messagePart->hasContent());
         $this->assertNull($messagePart->getContentResourceHandle());
-        $this->assertNotNull($messagePart->getHandle());
-        $handle = $messagePart->getHandle();
+        $this->assertNotNull($messagePart->getResourceHandle());
+        $handle = $messagePart->getResourceHandle();
         $this->assertEquals('mucha agua', stream_get_contents($handle));
     }
     
diff --git a/tests/MailMimeParser/Message/Part/MimePartTest.php b/tests/MailMimeParser/Message/Part/MimePartTest.php
index dfc2383e..9ca22415 100644
--- a/tests/MailMimeParser/Message/Part/MimePartTest.php
+++ b/tests/MailMimeParser/Message/Part/MimePartTest.php
@@ -112,9 +112,9 @@ public function testCreateChildrenAndGetChildren()
     {
         $part = $this->newMimePart($this->getMockedPartBuilderWithChildren());
         $this->assertEquals(3, $part->getChildCount());
-        $this->assertEquals('child0', stream_get_contents($part->getChild(0)->getHandle()));
-        $this->assertEquals('child1', stream_get_contents($part->getChild(1)->getHandle()));
-        $this->assertEquals('child2', stream_get_contents($part->getChild(2)->getHandle()));
+        $this->assertEquals('child0', stream_get_contents($part->getChild(0)->getResourceHandle()));
+        $this->assertEquals('child1', stream_get_contents($part->getChild(1)->getResourceHandle()));
+        $this->assertEquals('child2', stream_get_contents($part->getChild(2)->getResourceHandle()));
         $children = [
             $part->getChild(0),
             $part->getChild(1),
@@ -138,11 +138,11 @@ public function testCreateChildrenAndGetParts()
         $this->assertSame($children[1], $part->getPart(3));
         $this->assertSame($children[2], $part->getPart(4));
         
-        $this->assertEquals('habibi', stream_get_contents($part->getPart(0)->getHandle()));
-        $this->assertEquals('child0', stream_get_contents($part->getPart(1)->getHandle()));
-        $this->assertEquals('nested', stream_get_contents($part->getPart(2)->getHandle()));
-        $this->assertEquals('child1', stream_get_contents($part->getPart(3)->getHandle()));
-        $this->assertEquals('child2', stream_get_contents($part->getPart(4)->getHandle()));
+        $this->assertEquals('habibi', stream_get_contents($part->getPart(0)->getResourceHandle()));
+        $this->assertEquals('child0', stream_get_contents($part->getPart(1)->getResourceHandle()));
+        $this->assertEquals('nested', stream_get_contents($part->getPart(2)->getResourceHandle()));
+        $this->assertEquals('child1', stream_get_contents($part->getPart(3)->getResourceHandle()));
+        $this->assertEquals('child2', stream_get_contents($part->getPart(4)->getResourceHandle()));
         
         $allParts = [ $part, $children[0], $nested, $children[1], $children[2]];
         $this->assertEquals($allParts, $part->getAllParts());