diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,7 +36,7 @@
 )
 add_feature_info(QCH ${BUILD_QCH} "API documentation in QCH format (for e.g. Qt Assistant, Qt Creator & KDevelop)")
 
-set(REQUIRED_QT_VERSION "5.6.0")
+set(REQUIRED_QT_VERSION "5.9.0")
 
 find_package(Qt5 ${REQUIRED_QT_VERSION} REQUIRED NO_MODULE
     COMPONENTS