diff -Naur OpenImageIO-oiio-5b37f1c.orig/src/libOpenImageIO/CMakeLists.txt OpenImageIO-oiio-5b37f1c/src/libOpenImageIO/CMakeLists.txt
--- OpenImageIO-oiio-5b37f1c.orig/src/libOpenImageIO/CMakeLists.txt	2012-02-28 12:58:45.306847484 -0600
+++ OpenImageIO-oiio-5b37f1c/src/libOpenImageIO/CMakeLists.txt	2012-02-28 13:02:27.438365805 -0600
@@ -61,7 +61,11 @@
 endif ()
 
 # Include our own TBB if using it
-if (USE_TBB)
+if (USE_TBB AND USE_EXTERNAL_TBB)
+    message (STATUS "System TBB library will be used.")
+    set (libOpenImageIO_srcs ${libOpenImageIO_srcs})
+elseif (USE_TBB AND NOT USE_EXTERNAL_TBB)
+    message (STATUS "Built-in TBB library will be used.")
     set (libOpenImageIO_srcs ${libOpenImageIO_srcs} ../libutil/tbb_misc.cpp)
 endif ()
 
diff -Naur OpenImageIO-oiio-5b37f1c.orig/src/include/CMakeLists.txt OpenImageIO-oiio-5b37f1c/src/include/CMakeLists.txt
--- OpenImageIO-oiio-5b37f1c.orig/src/include/CMakeLists.txt	2012-02-25 17:17:12.000000000 -0600
+++ OpenImageIO-oiio-5b37f1c/src/include/CMakeLists.txt	2012-02-28 13:32:00.961799696 -0600
@@ -22,7 +22,7 @@
 install (FILES ${public_headers} DESTINATION ${INCLUDE_INSTALL_DIR}
          COMPONENT developer)
 
-if (USE_TBB)
+if (USE_TBB AND NOT USE_EXTERNAL_TBB)
     install (DIRECTORY tbb DESTINATION ${INCLUDE_INSTALL_DIR}
              COMPONENT developer)
 endif ()