diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b3763f549dced8be6e708b7be45ab44bfca39a2..de0bb256ef336d24a9db179e546bf2c9001ce9df 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -69,7 +69,7 @@ IF(NOT CLIENT_ONLY)
   SET(CMAKE_INCLUDE_CURRENT_DIR ON)
   IF(USE_QT4)
     FIND_PACKAGE(Qt4 REQUIRED QtCore QtGui QtOpenGl QtNetwork)
-    SET(PKG_CONFIG_EXTRA "qtversion: ${QT_VERSION_MAJOR}.${QT_VERSION_MINOR}.${QT_VERSION_PATCH}")
+    SET(PKG_CONFIG_EXTRA "qtversion=${QT_VERSION_MAJOR}.${QT_VERSION_MINOR}.${QT_VERSION_PATCH}")
   ELSE(USE_QT4)
     FOREACH (component "Core" "Widgets" "Gui" "OpenGL" "Network")
       FIND_PACKAGE ("Qt5${component}" REQUIRED)