diff --git a/autotests/data/mails/reply-header.mbox b/autotests/data/mails/reply-header.mbox
new file mode 100644
--- /dev/null
+++ b/autotests/data/mails/reply-header.mbox
@@ -0,0 +1,6 @@
+From null@kde.org Fri May 08 12:59:02 2020
+Reply: Weird Receiver <foo@kde.org>
+To: Volker Krause <vkrause@kde.org>
+From: Null <null@kde.org>
+
+Hi Volker,
diff --git a/autotests/messagetest.h b/autotests/messagetest.h
--- a/autotests/messagetest.h
+++ b/autotests/messagetest.h
@@ -47,6 +47,7 @@
     void testEncryptedMails();
     void testReturnSameMail();
     void testEmptySubject();
+    void testReplyHeader();
 
 private:
     KMime::Message::Ptr readAndParseMail(const QString &mailFile) const;
diff --git a/autotests/messagetest.cpp b/autotests/messagetest.cpp
--- a/autotests/messagetest.cpp
+++ b/autotests/messagetest.cpp
@@ -630,6 +630,16 @@
     QVERIFY(msg->subject()->asUnicodeString().isEmpty());
 }
 
+void MessageTest::testReplyHeader()
+{
+    auto msg = readAndParseMail(QStringLiteral("reply-header.mbox"));
+    QVERIFY(msg);
+    QVERIFY(!msg->replyTo(false));
+    QCOMPARE(msg->hasHeader("Reply-To"), false);
+    QCOMPARE(msg->hasHeader("Reply"), true);
+    QVERIFY(msg->headerByType("Reply"));
+}
+
 KMime::Message::Ptr MessageTest::readAndParseMail(const QString &mailFile) const
 {
     QFile file(QLatin1String(TEST_DATA_DIR) + QLatin1String("/mails/") + mailFile);
diff --git a/src/kmime_headerfactory.cpp b/src/kmime_headerfactory.cpp
--- a/src/kmime_headerfactory.cpp
+++ b/src/kmime_headerfactory.cpp
@@ -38,8 +38,8 @@
 using namespace KMime::Headers;
 
 #define mk_header(hdr) \
-    if (qstrnicmp(type, hdr ::staticType(), typeLen) == 0) \
-        return new hdr
+    if (qstrnicmp(type, hdr ::staticType(), std::max(typeLen, strlen(hdr::staticType()))) == 0) \
+        return new hdr;
 
 Headers::Base *HeaderFactory::createHeader(const char *type, size_t typeLen)
 {