diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,7 @@
 project(QtCurve)
 
 include(FeatureSummary)
+include(CMakeDependentOption)
 
 ## Temporary
 function(translate_add_sources)
@@ -31,47 +32,28 @@
   "${GIT_EXECUTABLE}"
   DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/version.cpp")
 
-## Options
-function(qtc_option name doc def_val)
-  if(DEFINED "${name}")
-    set("${name}_DEFINED" On PARENT_SCOPE)
-    option("${name}" "${doc}" On)
-  else()
-    set("${name}_DEFINED" Off PARENT_SCOPE)
-    option("${name}" "${doc}" "${def_val}")
-  endif()
-endfunction()
 function(qtc_variable name doc def_val)
   if(DEFINED "${name}")
     set("${name}_DEFINED" On PARENT_SCOPE)
   else()
     set("${name}_DEFINED" Off PARENT_SCOPE)
     set("${name}" "${def_val}" PARENT_SCOPE)
   endif()
 endfunction()
-qtc_option(ENABLE_QT4 "Building Qt4 theme." On)
-qtc_option(ENABLE_QT5 "Building Qt5 theme." On)
-qtc_option(ENABLE_GTK2 "Building Gtk2 theme." On)
+option(ENABLE_QT4 "Building Qt4 theme." ON)
+option(ENABLE_QT5 "Building Qt5 theme." ON)
+option(ENABLE_GTK2 "Building Gtk2 theme." ON)
 # option(ENABLE_GTK3 "Building Gtk3 theme." On)
 option(ENABLE_TEST "Enable testing." On)
 option(QTC_ENABLE_X11 "Enable X11" On)
 option(QTC_INSTALL_PO "Install translation files." On)
 
-if(ENABLE_QT4)
-    qtc_option(QTC_QT4_ENABLE_KDE "Building Qt4 style with KDE4 support." On)
-else()
-    qtc_option(QTC_QT4_ENABLE_KDE "Building Qt4 style with KDE4 support." Off)
-endif()
-if(ENABLE_QT5)
-    qtc_option(QTC_QT5_ENABLE_KDE
-      "Building Qt5 style with KDE Frameworks 5 support." On)
-else()
-    qtc_option(QTC_QT5_ENABLE_KDE
-      "Building Qt5 style with KDE Frameworks 5 support." Off)
-endif()
+cmake_dependent_option(QTC_QT4_ENABLE_KDE "Building Qt4 style with KDE4 support." ON
+                       "ENABLE_QT4" OFF)
+cmake_dependent_option(QTC_QT5_ENABLE_KDE "Building Qt4 style with KDE Frameworks 5 support." ON
+                       "ENABLE_QT5" OFF)
 
-option(QTC_QT4_STYLE_SUPPORT
-  "Qt4 support for creating a style for each QtCurve theme." Off)
+cmake_dependent_option(QTC_QT4_STYLE_SUPPORT "Qt4 support for creating a style for each QtCurve theme." OFF "ENABLE_QT4" OFF)
 
 ## Common settings.
 # support an infix argument to have different qtcurve-utils libraries, e.g. for
diff --git a/qt4/CMakeLists.txt b/qt4/CMakeLists.txt
--- a/qt4/CMakeLists.txt
+++ b/qt4/CMakeLists.txt
@@ -1,4 +1,4 @@
-if(ENABLE_QT4 AND NOT ENABLE_QT4_DEFINED)
+if(ENABLE_QT4)
   # ENABLE_QT4 is not defined on the command line
   find_package(Qt4 4.6.0)
   if(NOT Qt4_FOUND AND NOT QT4_FOUND)
diff --git a/qt5/CMakeLists.txt b/qt5/CMakeLists.txt
--- a/qt5/CMakeLists.txt
+++ b/qt5/CMakeLists.txt
@@ -7,9 +7,8 @@
   set(QTC_QT5_MODULES ${QTC_QT5_MODULES} Qt5PrintSupport)
 endif()
 
-if(ENABLE_QT5 AND NOT ENABLE_QT5_DEFINED)
+if(ENABLE_QT5)
   set(QT_MIN_VERSION "5.3.2")
-  # ENABLE_QT5 is not defined on the command line
   foreach(QtModule ${QTC_QT5_MODULES})
     find_package(${QtModule} ${QT_MIN_VERSION} CONFIG)
     if(NOT ${QtModule}_FOUND)