diff --git a/matrix/Euler.hpp b/matrix/Euler.hpp
index 2928baa6ad..57dcbb48a2 100644
--- a/matrix/Euler.hpp
+++ b/matrix/Euler.hpp
@@ -10,6 +10,10 @@
 
 #include "math.hpp"
 
+#ifndef M_PI
+#define M_PI (3.14159265358979323846f)
+#endif
+
 namespace matrix
 {
 
diff --git a/matrix/Matrix.hpp b/matrix/Matrix.hpp
index 5c59593318..c9c88b4efe 100644
--- a/matrix/Matrix.hpp
+++ b/matrix/Matrix.hpp
@@ -371,7 +371,7 @@ public:
         setZero();
         Matrix<Type, M, N> &self = *this;
 
-        for (size_t i = 0; i < M and i < N; i++) {
+        for (size_t i = 0; i < M && i < N; i++) {
             self(i, i) = 1;
         }
     }