--- CMakeLists.txt.orig	2017-08-28 16:50:49 UTC
+++ CMakeLists.txt
@@ -252,6 +252,9 @@ ENDIF()
 
 INCLUDE_DIRECTORIES(
     ${OpenSceneGraph_SOURCE_DIR}/include
+)
+
+INCLUDE_DIRECTORIES(SYSTEM
     ${OPENGL_INCLUDE_DIR}
 )
 
@@ -846,7 +849,7 @@ ENDIF()
 
 IF(UNIX AND NOT WIN32 AND NOT APPLE)
   IF(CMAKE_SIZEOF_VOID_P MATCHES "8")
-      SET(LIB_POSTFIX "64" CACHE STRING "suffix for 32/64 dir placement")
+      SET(LIB_POSTFIX "" CACHE STRING "suffix for 32/64 dir placement")
       MARK_AS_ADVANCED(LIB_POSTFIX)
   ENDIF()
 ENDIF()
@@ -1275,7 +1278,7 @@ FOREACH(PKGCONFIG_FILE ${PKGCONFIG_FILES
     ${PROJECT_BINARY_DIR}/packaging/pkgconfig/${PKGCONFIG_FILE}.pc
     @ONLY
     )
-  INSTALL(FILES ${PROJECT_BINARY_DIR}/packaging/pkgconfig/${PKGCONFIG_FILE}.pc DESTINATION lib${LIB_POSTFIX}/pkgconfig COMPONENT libopenscenegraph-dev)
+  INSTALL(FILES ${PROJECT_BINARY_DIR}/packaging/pkgconfig/${PKGCONFIG_FILE}.pc DESTINATION libdata/pkgconfig COMPONENT libopenscenegraph-dev)
 ENDFOREACH(PKGCONFIG_FILE)