diff --git a/configs/config-suite-b.h b/configs/config-suite-b.h
index 4651e0df2..0600c2e1c 100644
--- a/configs/config-suite-b.h
+++ b/configs/config-suite-b.h
@@ -60,8 +60,8 @@
 #define POLARSSL_AES_ROM_TABLES
 
 /* Save RAM by adjusting to our exact needs */
-#define POLARSSL_MPI_MAX_SIZE    96
 #define POLARSSL_ECP_MAX_BITS   384
+#define POLARSSL_MPI_MAX_SIZE    48 // 384 bits is 48 bytes
 
 /* Save RAM at the expense of speed, see ecp.h */
 #define POLARSSL_ECP_WINDOW_SIZE        2