diff --git a/kf5-akonadi-contacts.spec b/kf5-akonadi-contacts.spec
index 17b5507..674e5a7 100644
--- a/kf5-akonadi-contacts.spec
+++ b/kf5-akonadi-contacts.spec
@@ -46,7 +46,9 @@ BuildRequires:  cmake(Qt5Widgets) >= 5.8
 %global majmin_ver %{version}
 BuildRequires:  kf5-akonadi-mime-devel >= %{majmin_ver}
 BuildRequires:  kf5-akonadi-server-devel >= %{majmin_ver}
+%if !(0%{?rhel} == 8 && ( %{_arch} == "aarch64" || %{_arch} == "s390x" ))
 BuildRequires:  kf5-kcalendarcore-devel >= %{majmin_ver}
+%endif
 BuildRequires:  kf5-kcontacts-devel >= %{majmin_ver}
 BuildRequires:  kf5-kmime-devel >= %{majmin_ver}
 
@@ -73,7 +75,7 @@ Obsoletes: kf5-akonadi-contact-devel < 16.07
 Provides:  kf5-akonadi-contact-devel = %{version}-%{release}
 Requires:  cmake(KF5Akonadi)
 Requires:  cmake(KF5Contacts)
-Requires:  cmake(KF5CalendarCore)
+Recommends:  cmake(KF5CalendarCore)
 %description    devel
 The %{name}-devel package contains libraries and header files for
 developing applications that use %{name}.