diff --git a/freeglut/freeglut/CMakeLists.txt b/freeglut/freeglut/CMakeLists.txt
index 909884c..43555fb 100644
--- a/freeglut/freeglut/CMakeLists.txt
+++ b/freeglut/freeglut/CMakeLists.txt
@@ -257,6 +257,7 @@ ENDIF(CMAKE_COMPILER_IS_GNUCC)
 INCLUDE(CheckIncludeFiles)
 IF(UNIX AND NOT(ANDROID OR BLACKBERRY))
     FIND_PACKAGE(X11 REQUIRED)
+    INCLUDE_DIRECTORIES(${X11_INCLUDE_DIR})
     LIST(APPEND LIBS ${X11_LIBRARIES})
     IF(X11_Xrandr_FOUND)
         SET(HAVE_X11_EXTENSIONS_XRANDR_H TRUE)