diff --git a/sys/net/include/rpl/rpl_config.h b/sys/net/include/rpl/rpl_config.h
index c725f75c85..9720b14116 100644
--- a/sys/net/include/rpl/rpl_config.h
+++ b/sys/net/include/rpl/rpl_config.h
@@ -57,7 +57,8 @@ enum RPL_MSG_CODE {
 #define RPL_OPT_LEN                             2
 #define RPL_OPT_DODAG_CONF_LEN                  14
 #define RPL_OPT_DODAG_CONF_LEN_WITH_OPT_LEN     (RPL_OPT_DODAG_CONF_LEN + RPL_OPT_LEN)
-#define RPL_OPT_PREFIX_INFO_LEN                 32
+#define RPL_OPT_PREFIX_INFO_LEN                 30
+#define RPL_OPT_PREFIX_INFO_LEN_WITH_OPT_LEN    (RPL_OPT_PREFIX_INFO_LEN + RPL_OPT_LEN)
 #define RPL_OPT_SOLICITED_INFO_LEN              21
 #define RPL_OPT_TARGET_LEN                      20
 #define RPL_OPT_TRANSIT_LEN                     22
diff --git a/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c b/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
index e2d5e19222..91e1adc52c 100644
--- a/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
+++ b/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
@@ -488,12 +488,12 @@ void rpl_recv_DIO_mode(void)
             }
 
             case (RPL_OPT_PREFIX_INFO): {
-                if (rpl_opt_buf->length != (RPL_OPT_PREFIX_INFO_LEN - RPL_OPT_LEN)) {
+                if (rpl_opt_buf->length != RPL_OPT_PREFIX_INFO_LEN) {
                     /* error malformed */
                     return;
                 }
 
-                len += RPL_OPT_PREFIX_INFO_LEN;
+                len += RPL_OPT_PREFIX_INFO_LEN_WITH_OPT_LEN;
                 break;
             }
 
diff --git a/sys/net/routing/rpl/rpl_storing/rpl_storing.c b/sys/net/routing/rpl/rpl_storing/rpl_storing.c
index d06cb506e8..adc053c895 100644
--- a/sys/net/routing/rpl/rpl_storing/rpl_storing.c
+++ b/sys/net/routing/rpl/rpl_storing/rpl_storing.c
@@ -519,12 +519,12 @@ void rpl_recv_DIO_mode(void)
             }
 
             case (RPL_OPT_PREFIX_INFO): {
-                if (rpl_opt_buf->length != (RPL_OPT_PREFIX_INFO_LEN - RPL_OPT_LEN)) {
+                if (rpl_opt_buf->length != RPL_OPT_PREFIX_INFO_LEN) {
                     /* error malformed */
                     return;
                 }
 
-                len += RPL_OPT_PREFIX_INFO_LEN;
+                len += RPL_OPT_PREFIX_INFO_LEN_WITH_OPT_LEN;
                 break;
             }