diff --git a/contrib/openddlparser/code/OpenDDLParser.cpp b/contrib/openddlparser/code/OpenDDLParser.cpp
index 4b9313a42..186323730 100644
--- a/contrib/openddlparser/code/OpenDDLParser.cpp
+++ b/contrib/openddlparser/code/OpenDDLParser.cpp
@@ -26,6 +26,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <iostream>
 #include <sstream>
 #include <algorithm>
+#include <math.h>
 
 #ifdef _WIN32
 #  include <windows.h>