--- virtualbox.spec~    2017-07-28 11:50:57.271793893 +0300
+++ virtualbox.spec     2017-07-28 11:51:06.116793846 +0300
@@ -345,7 +345,7 @@ export GCC_VERSION=%gcc_version
 %if_without manual
     --disable-docs \
 %endif    
-    --with-qt-dir=%_qt5_prefix \
+    --enable-qt5 \
 
 
 kbuild=%_bindir