diff --git a/urdf_parser/test/urdf_unit_test.cpp b/urdf_parser/test/urdf_unit_test.cpp
index 3e011b6f..cb204a56 100644
--- a/urdf_parser/test/urdf_unit_test.cpp
+++ b/urdf_parser/test/urdf_unit_test.cpp
@@ -5,6 +5,9 @@
 #include <vector>
 #include "urdf_model/pose.h"
 
+#ifndef M_PI
+# define M_PI 3.141592653589793
+#endif
 
 bool quat_are_near(urdf::Rotation left, urdf::Rotation right)
 {