diff --git a/cpp/patchworkpp/include/patchwork/patchworkpp.h b/cpp/patchworkpp/include/patchwork/patchworkpp.h
index a6e71f7..7ab4e01 100755
--- a/cpp/patchworkpp/include/patchwork/patchworkpp.h
+++ b/cpp/patchworkpp/include/patchwork/patchworkpp.h
@@ -1,6 +1,10 @@
 #ifndef PATCHWORKPP_H
 #define PATCHWORKPP_H
 
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include <iostream>
 #include <vector>
 #include <Eigen/Dense>