diff --git a/CMakeLists.txt b/CMakeLists.txt
index a77dce8d5..d97f5f0ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -330,16 +330,15 @@ IF(UNIX AND NOT ANDROID)
 
 ENDIF()
 
-INCLUDE_DIRECTORIES(
-    ${OpenSceneGraph_SOURCE_DIR}/include
-    ${OPENGL_INCLUDE_DIR}
-)
+INCLUDE_DIRECTORIES(${OpenSceneGraph_SOURCE_DIR}/include/)
 
 # Make the headers visible to everything
 IF(NOT ${PROJECT_BINARY_DIR} EQUAL ${PROJECT_SOURCE_DIR})
    INCLUDE_DIRECTORIES(${PROJECT_BINARY_DIR}/include)
 ENDIF()
 
+INCLUDE_DIRECTORIES(SYSTEM ${OPENGL_INCLUDE_DIR})
+
 # Common global definitions
 #ADD_DEFINITIONS(-D)
 # Platform specific definitions