diff --git a/qad/doc/CMakeLists.txt b/qad/doc/CMakeLists.txt
index 893b649..a3740cf 100644
--- a/qad/doc/CMakeLists.txt
+++ b/qad/doc/CMakeLists.txt
@@ -1,9 +1,9 @@
-include(CheckIncludeFileCXX)
 find_library(MARKDOWN_LIBRARY markdown)
 set(_LIBS)
 if (MARKDOWN_LIBRARY)
 	list(APPEND _LIBS "${MARKDOWN_LIBRARY}")
 	add_definitions("-DUSE_MARKDOWN")
+	include(CheckIncludeFileCXX)
 	set(CHECK_INCLUDES "-include stdio.h")
 	if(WIN32)
 		set(CHECK_INCLUDES "-include windows.h -include stdio.h")