diff --git a/gfx/graphite2/src/Collider.cpp b/gfx/graphite2/src/Collider.cpp
--- a/gfx/graphite2/src/Collider.cpp
+++ b/gfx/graphite2/src/Collider.cpp
@@ -21,17 +21,17 @@
 
 Alternatively, the contents of this file may be used under the terms of the
 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public
 License, as published by the Free Software Foundation, either version 2
 of the License or (at your option) any later version.
 */
 #include <algorithm>
 #include <limits>
-#include <math.h>
+#include <cmath>
 #include <string>
 #include <functional>
 #include "inc/Collider.h"
 #include "inc/Segment.h"
 #include "inc/Slot.h"
 #include "inc/GlyphCache.h"
 #include "inc/Sparse.h"