diff --git a/src/lib/core/KdTree.h b/src/lib/core/KdTree.h
index 9c14e205..b7f66d5c 100644
--- a/src/lib/core/KdTree.h
+++ b/src/lib/core/KdTree.h
@@ -34,7 +34,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 */
 #ifndef KdTree_h
 #define KdTree_h
+#if defined(__clang__) && defined(_LIBCPP_VERSION)
+#include <numeric>
+#elif defined(__GNUC__)
 #include <ext/numeric>
+#endif
 
 namespace Partio
 {
@@ -286,7 +290,11 @@ void KdTree<k>::setPoints(const float* p, int n)
 
     // assign sequential ids
     _ids.resize(n);
+#if defined(__clang__) && defined(_LIBCPP_VERSION)
+    std::iota(_ids.begin(), _ids.end(), 0);
+#elif defined(__GNUC__)
     __gnu_cxx::iota(_ids.begin(), _ids.end(), 0);
+#endif
 //    _ids.reserve(n);
 //    while ((int)_ids.size() < n) _ids.push_back(_ids.size());
     _sorted = 0;
diff --git a/src/tools/CMakeLists.txt b/src/tools/CMakeLists.txt
index 1d6a0cd5..9810cecc 100644
--- a/src/tools/CMakeLists.txt
+++ b/src/tools/CMakeLists.txt
@@ -36,6 +36,7 @@ include_directories(
 )
 
 IF(GLUT_FOUND AND OPENGL_FOUND)
+    INCLUDE_DIRECTORIES(${GLUT_INCLUDE_DIR} ${OPENGL_INCLUDE_DIR})
     ADD_EXECUTABLE(partview partview.cpp)
     target_link_libraries(partview ${PARTIO_LIBRARIES} ${GLUT_LIBRARY} ${OPENGL_LIBRARY})
     install(TARGETS  partview DESTINATION bin)