diff --git a/messageviewer/src/viewer/bodypartformatter.cpp b/messageviewer/src/viewer/bodypartformatter.cpp
--- a/messageviewer/src/viewer/bodypartformatter.cpp
+++ b/messageviewer/src/viewer/bodypartformatter.cpp
@@ -142,6 +142,45 @@
     }
 }
 
+class MultiPartSignedBodyPartFormatter
+    : public MessageViewer::Interface::BodyPartFormatter
+{
+public:
+    MessagePart::Ptr process(const Interface::BodyPart &part) const;
+    MessageViewer::Interface::BodyPartFormatter::Result format(Interface::BodyPart *, HtmlWriter *) const Q_DECL_OVERRIDE;
+    using MessageViewer::Interface::BodyPartFormatter::format;
+    static const MessageViewer::Interface::BodyPartFormatter *create();
+private:
+    static const MultiPartSignedBodyPartFormatter *self;
+};
+
+const MultiPartSignedBodyPartFormatter *MultiPartSignedBodyPartFormatter::self;
+
+const MessageViewer::Interface::BodyPartFormatter *MultiPartSignedBodyPartFormatter::create()
+{
+    if (!self) {
+        self = new MultiPartSignedBodyPartFormatter();
+    }
+    return self;
+}
+
+MessagePart::Ptr MultiPartSignedBodyPartFormatter::process(const Interface::BodyPart &part) const
+{
+    return part.objectTreeParser()->processMultiPartSignedSubtype(part.content(), *part.processResult());
+}
+
+MessageViewer::Interface::BodyPartFormatter::Result MultiPartSignedBodyPartFormatter::format(Interface::BodyPart *part, HtmlWriter *writer) const
+{
+    Q_UNUSED(writer)
+    MessagePart::Ptr mp = process(*part);
+    if (!mp.isNull()) {
+        mp->html(false);
+        return Ok;
+    }
+
+    return Failed;
+}
+
 #define CREATE_BODY_PART_FORMATTER(subtype) \
     class subtype##BodyPartFormatter \
         : public MessageViewer::Interface::BodyPartFormatter \
@@ -182,7 +221,6 @@
 
 CREATE_BODY_PART_FORMATTER(MultiPartMixed)
 CREATE_BODY_PART_FORMATTER(MultiPartAlternative)
-CREATE_BODY_PART_FORMATTER(MultiPartSigned)
 CREATE_BODY_PART_FORMATTER(MultiPartEncrypted)
 
 typedef TextPlainBodyPartFormatter ApplicationPgpBodyPartFormatter;
diff --git a/messageviewer/src/viewer/objecttreeparser.h b/messageviewer/src/viewer/objecttreeparser.h
--- a/messageviewer/src/viewer/objecttreeparser.h
+++ b/messageviewer/src/viewer/objecttreeparser.h
@@ -420,7 +420,7 @@
     bool processMultiPartAlternativeSubtype(KMime::Content *node, ProcessResult &result);
     bool processMultiPartDigestSubtype(KMime::Content *node, ProcessResult &result);
     bool processMultiPartParallelSubtype(KMime::Content *node, ProcessResult &result);
-    bool processMultiPartSignedSubtype(KMime::Content *node, ProcessResult &result);
+    MessagePart::Ptr processMultiPartSignedSubtype(KMime::Content *node, ProcessResult &result);
     bool processMultiPartEncryptedSubtype(KMime::Content *node, ProcessResult &result);
 
     bool processApplicationPkcs7MimeSubtype(KMime::Content *node, ProcessResult &result);
diff --git a/messageviewer/src/viewer/objecttreeparser.cpp b/messageviewer/src/viewer/objecttreeparser.cpp
--- a/messageviewer/src/viewer/objecttreeparser.cpp
+++ b/messageviewer/src/viewer/objecttreeparser.cpp
@@ -1168,16 +1168,14 @@
     return processMultiPartMixedSubtype(node, result);
 }
 
-bool ObjectTreeParser::processMultiPartSignedSubtype(KMime::Content *node, ProcessResult &)
+MessagePart::Ptr ObjectTreeParser::processMultiPartSignedSubtype(KMime::Content *node, ProcessResult &)
 {
     KMime::Content *child = MessageCore::NodeHelper::firstChild(node);
     if (node->contents().size() != 2) {
         qCDebug(MESSAGEVIEWER_LOG) << "mulitpart/signed must have exactly two child parts!" << endl
                                    << "processing as multipart/mixed";
-        if (child) {
-            standardChildHandling(child);
-        }
-        return child;
+
+        return MessagePart::Ptr(new MimeMessagePart(this, child, false));
     }
 
     KMime::Content *signedData = child;
@@ -1189,8 +1187,7 @@
     mNodeHelper->setNodeProcessed(signature, true);
 
     if (!includeSignatures()) {
-        standardChildHandling(signedData);
-        return true;
+        return MessagePart::Ptr(new MimeMessagePart(this, signedData, false));
     }
 
     QString protocolContentType = node->contentType()->parameter(QStringLiteral("protocol")).toLower();
@@ -1212,30 +1209,28 @@
 
     if (!protocol) {
         mNodeHelper->setNodeProcessed(signature, true);
-        standardChildHandling(signedData);
-        return true;
+        return MessagePart::Ptr(new MimeMessagePart(this, signedData, false));
     }
 
     CryptoProtocolSaver saver(this, protocol);
     mNodeHelper->setSignatureState(node, KMMsgFullySigned);
 
     const QByteArray cleartext = KMime::LFtoCRLF(signedData->encodedContent());
     const QTextCodec *aCodec(codecFor(signedData));
 
-    CryptoMessagePart mp(this, &messagePart,
+    CryptoMessagePart::Ptr mp(new CryptoMessagePart(this,
                          aCodec->toUnicode(cleartext), cryptoProtocol(),
-                         NodeHelper::fromAsString(node), signature);
-    messagePart.isSigned = true;
+                         NodeHelper::fromAsString(node), signature));
+    PartMetaData *messagePart(mp->partMetaData());
+    messagePart->isSigned = true;
 
     if (cryptoProtocol()) {
-        mp.startVerificationDetached(cleartext, signedData, signature->decodedContent());
+        mp->startVerificationDetached(cleartext, signedData, signature->decodedContent());
     } else {
         messagePart->auditLogError = GpgME::Error(GPG_ERR_NOT_IMPLEMENTED);
     }
 
-    mp.html(false);
-
-    return true;
+    return mp;
 }
 
 bool ObjectTreeParser::processMultiPartEncryptedSubtype(KMime::Content *node, ProcessResult &result)