diff --git a/src/osgEarth/Ellipsoid.cpp b/src/osgEarth/Ellipsoid.cpp
index d95ffe20ec..e69fe3fb63 100644
--- a/src/osgEarth/Ellipsoid.cpp
+++ b/src/osgEarth/Ellipsoid.cpp
@@ -19,6 +19,7 @@
 #include "Ellipsoid"
 #include <osg/CoordinateSystemNode>
 #include <osgEarth/Notify>
+#include <algorithm>
 
 using namespace osgEarth;