Make ecp_supported_curves constant
diff --git a/include/polarssl/ecp.h b/include/polarssl/ecp.h
index ae45c6e..1d18b14 100644
--- a/include/polarssl/ecp.h
+++ b/include/polarssl/ecp.h
@@ -76,7 +76,7 @@
 /**
  * List of supported curves
  */
-extern ecp_curve_info ecp_supported_curves[];
+extern const ecp_curve_info ecp_supported_curves[];
 
 /**
  * \brief           ECP point structure (jacobian coordinates)