diff --git a/scripts/ecc-heap.sh b/scripts/ecc-heap.sh
index d985fa20c..5053fa717 100755
--- a/scripts/ecc-heap.sh
+++ b/scripts/ecc-heap.sh
@@ -71,7 +71,10 @@ cat << EOF >$CONFIG_H
 
 #include "check_config.h"
 
-//#define MBEDTLS_ECP_WINDOW_SIZE            6
+#define MBEDTLS_HAVE_ASM // just make things a bit faster
+#define MBEDTLS_ECP_NIST_OPTIM // faster and less allocations
+
+//#define MBEDTLS_ECP_WINDOW_SIZE            4
 //#define MBEDTLS_ECP_FIXED_POINT_OPTIM      1
 EOF