diff --git a/configs/config-ccm-psk-tls1_2.h b/configs/config-ccm-psk-tls1_2.h
index c80c912ed..1da9f6a6b 100644
--- a/configs/config-ccm-psk-tls1_2.h
+++ b/configs/config-ccm-psk-tls1_2.h
@@ -13,7 +13,7 @@
 
 /* System support */
 //#define POLARSSL_HAVE_IPV6 /* Optional */
-//#define POLARSSL_HAVE_TIME /* Optionnaly used in Hello messages */
+//#define POLARSSL_HAVE_TIME /* Optionally used in Hello messages */
 /* Other POLARSSL_HAVE_XXX flags irrelevant for this configuration */
 
 /* PolarSSL feature support */
@@ -36,6 +36,9 @@
 /* Save RAM at the expense of ROM */
 #define POLARSSL_AES_ROM_TABLES
 
+/* Save some RAM by adjusting to your exact needs */
+#define POLARSSL_PSK_MAX_LEN    16 /* 128-bits keys are generally enough */
+
 /*
  * You should adjust this to the exact number of sources you're using: default
  * is the "platform_entropy_poll" source, but you may want to add other ones
@@ -50,9 +53,10 @@
 #define SSL_CIPHERSUITES                        \
         TLS_PSK_WITH_AES_256_CCM_8,             \
         TLS_PSK_WITH_AES_128_CCM_8
+
 /*
  * Save RAM at the expense of interoperability: do this only if you control
- * both ends of the connection!  (See coments in "polarssl/ssl.h".)
+ * both ends of the connection!  (See comments in "polarssl/ssl.h".)
  * The optimal size here depends on the typical size of records.
  */
 #define SSL_MAX_CONTENT_LEN             512