diff --git a/Breeze-dark-gtk/CMakeLists.txt b/Breeze-dark-gtk/CMakeLists.txt
index 4cafdd8..15fbb2f 100644
--- a/Breeze-dark-gtk/CMakeLists.txt
+++ b/Breeze-dark-gtk/CMakeLists.txt
@@ -1,10 +1,10 @@
 install(DIRECTORY gtk-2.0 DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze-Dark
     ${directory_EXCLUDES})
 install(DIRECTORY assets DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze-Dark
         ${directory_EXCLUDES})
 
-if (WITH_GTK3_VERSION VERSION_LESS "3.20")
+if (PKG_GTK_VERSION VERSION_LESS "3.20")
 install(FILES gtk-3.18/gtk.css DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze-Dark/gtk-3.0/)
 else()
 install(FILES gtk-3.20/gtk.css DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze-Dark/gtk-3.0/)
 endif()
diff --git a/Breeze-gtk/CMakeLists.txt b/Breeze-gtk/CMakeLists.txt
index 957665f..5096c28 100644
--- a/Breeze-gtk/CMakeLists.txt
+++ b/Breeze-gtk/CMakeLists.txt
@@ -1,10 +1,10 @@
 install(DIRECTORY gtk-2.0 DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze
     ${directory_EXCLUDES})
 install(DIRECTORY assets DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze
         ${directory_EXCLUDES})
 
-if (WITH_GTK3_VERSION VERSION_LESS "3.20")
+if (PKG_GTK_VERSION VERSION_LESS "3.20")
 install(FILES gtk-3.18/gtk.css DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze/gtk-3.0/)
 else()
 install(FILES gtk-3.20/gtk.css DESTINATION ${KDE_INSTALL_FULL_DATAROOTDIR}/themes/Breeze/gtk-3.0/)
 endif()
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 78869f6..0526c17 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,30 +1,30 @@
 project(breeze-gtk)
 set(PROJECT_VERSION "5.9.90")
 set(PROJECT_VERSION_MAJOR 5)
 
 cmake_minimum_required(VERSION 2.8.12)
 
 find_package(ECM 0.0.9 REQUIRED NO_MODULE)
 include(FeatureSummary)
 
-set(WITH_GTK3_VERSION 3.18 CACHE STRING
-    "Use the theme for the specified GTK+3 version (default: 3.18)")
-
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR} "${CMAKE_SOURCE_DIR}/cmake")
+find_package(GTKEngine)
+
+find_package(PkgConfig)
+pkg_check_modules(PKG_GTK REQUIRED gtk+-3.0)
+
 include(KDEInstallDirs)
 
 # Exclude these patterns when installing directories as they have no use
 # in production.
 set(directory_EXCLUDES
     PATTERN "render-assets.sh" EXCLUDE
     PATTERN "assets.svg" EXCLUDE
     PATTERN "assets.txt" EXCLUDE
 )
 
 add_subdirectory(Breeze-dark-gtk)
 add_subdirectory(Breeze-gtk)
 add_subdirectory(kconf_update)
 
-find_package(GTKEngine)
-
 feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)