diff --git a/kdecoration.spec b/kdecoration.spec
index 4e83613..033973e 100644
--- a/kdecoration.spec
+++ b/kdecoration.spec
@@ -1,4 +1,4 @@
-
+%undefine __cmake_in_source_build
 # uncomment to enable bootstrap mode
 #global bootstrap 1
 
@@ -59,17 +59,13 @@ sed -i "s/set(KDECORATION2_INCLUDEDIR \"\${CMAKE_INSTALL_INCLUDEDIR}\/KDecoratio
 
 
 %build
-mkdir %{_target_platform}
-pushd %{_target_platform}
-%{cmake_kf5} .. \
+%{cmake_kf5} \
   -DBUILD_TESTING:BOOL=%{?tests:ON}%{!?tests:OFF}
-popd
-
-%make_build -C %{_target_platform}
+%cmake_build
 
 
 %install
-make install/fast DESTDIR=%{buildroot} -C %{_target_platform}
+%cmake_install
 
 # create/own plugin dir
 mkdir -p %{buildroot}%{_kf5_qtplugindir}/org.kde.kdecoration2/