diff --git a/Mesh/Matrix.h b/Mesh/Matrix.h
index d5f03944b9ba4f4bb561930752921ad0d19594cf..36ca7e353982fba9123309bb4bf7fa18d62f86c9 100644
--- a/Mesh/Matrix.h
+++ b/Mesh/Matrix.h
@@ -70,7 +70,7 @@ class Vector3
 
 	  double m = zero;
 	  for(int i=0;i<_TAILLE_;i++)
-	    m + mat[i] * autre.mat[i];
+	    m += mat[i] * autre.mat[i];
 	  return m;
       }
 };