Only build Qt sources is specified
diff --git a/src/main/CMakeLists.txt b/src/main/CMakeLists.txt
index 16a7c8a..692ed2f 100644
--- a/src/main/CMakeLists.txt
+++ b/src/main/CMakeLists.txt
@@ -9,6 +9,9 @@
   $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
 )
-target_include_directories(log4cxx-qt PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-)
+
+if(LOG4CXX_QT_SUPPORT)
+    target_include_directories(log4cxx-qt PUBLIC
+      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    )
+endif(LOG4CXX_QT_SUPPORT)