diff --git a/configs/config-ccm-psk-tls1_2.h b/configs/config-ccm-psk-tls1_2.h
index 0c6d128c..f425391d 100644
--- a/configs/config-ccm-psk-tls1_2.h
+++ b/configs/config-ccm-psk-tls1_2.h
@@ -12,8 +12,9 @@
 #define POLARSSL_CONFIG_H
 
 /* System support */
-#define POLARSSL_HAVE_IPV6
-#define POLARSSL_HAVE_TIME
+//#define POLARSSL_HAVE_IPV6 /* Optional */
+//#define POLARSSL_HAVE_TIME /* Optionnaly used in Hello messages */
+/* Other POLARSSL_HAVE_XXX flags irrelevant for this configuration */
 
 /* PolarSSL feature support */
 #define POLARSSL_KEY_EXCHANGE_PSK_ENABLED
diff --git a/configs/config-psk-rc4-tls1_0.h b/configs/config-psk-rc4-tls1_0.h
index ef995e81..e4fc4520 100644
--- a/configs/config-psk-rc4-tls1_0.h
+++ b/configs/config-psk-rc4-tls1_0.h
@@ -12,8 +12,9 @@
 #define POLARSSL_CONFIG_H
 
 /* System support */
-#define POLARSSL_HAVE_TIME
-#define POLARSSL_HAVE_IPV6
+//#define POLARSSL_HAVE_IPV6 /* Optional */
+//#define POLARSSL_HAVE_TIME /* Optionnaly used in Hello messages */
+/* Other POLARSSL_HAVE_XXX flags irrelevant for this configuration */
 
 /* PolarSSL feature support */
 #define POLARSSL_KEY_EXCHANGE_PSK_ENABLED