diff --git a/resources/ews/ewsclient/ewsrecurrence.h b/resources/ews/ewsclient/ewsrecurrence.h
--- a/resources/ews/ewsclient/ewsrecurrence.h
+++ b/resources/ews/ewsclient/ewsrecurrence.h
@@ -30,7 +30,7 @@
     EwsRecurrence();
     explicit EwsRecurrence(QXmlStreamReader &reader);
     EwsRecurrence(const EwsRecurrence &other);
-    EwsRecurrence &operator=(const EwsRecurrence &other);
+    EwsRecurrence &operator=(const EwsRecurrence &other) = delete;
 private:
     bool readRelativeYearlyRecurrence(QXmlStreamReader &reader);
     bool readAbsoluteYearlyRecurrence(QXmlStreamReader &reader);
diff --git a/resources/ews/ewsclient/ewsrecurrence.cpp b/resources/ews/ewsclient/ewsrecurrence.cpp
--- a/resources/ews/ewsclient/ewsrecurrence.cpp
+++ b/resources/ews/ewsclient/ewsrecurrence.cpp
@@ -130,13 +130,6 @@
 {
 }
 
-EwsRecurrence &EwsRecurrence::operator=(const EwsRecurrence &other)
-{
-    *static_cast<Recurrence *>(this) = static_cast<Recurrence>(other);
-
-    return *this;
-}
-
 bool EwsRecurrence::readRelativeYearlyRecurrence(QXmlStreamReader &reader)
 {
     QBitArray dow(7);