diff --git a/sys/net/routing/rpl/of0.c b/sys/net/routing/rpl/of0.c
index 5c7c479746..913be73b87 100644
--- a/sys/net/routing/rpl/of0.c
+++ b/sys/net/routing/rpl/of0.c
@@ -27,7 +27,7 @@ static rpl_parent_t *which_parent(rpl_parent_t *, rpl_parent_t *);
 static rpl_dodag_t *which_dodag(rpl_dodag_t *, rpl_dodag_t *);
 static void reset(rpl_dodag_t *);
 
-rpl_of_t rpl_of0 = {
+static rpl_of_t rpl_of0 = {
     0x0,
     calc_rank,
     which_parent,
diff --git a/sys/net/routing/rpl/of_mrhof.c b/sys/net/routing/rpl/of_mrhof.c
index 367c041858..83eb3bb285 100644
--- a/sys/net/routing/rpl/of_mrhof.c
+++ b/sys/net/routing/rpl/of_mrhof.c
@@ -34,10 +34,10 @@ static rpl_dodag_t *which_dodag(rpl_dodag_t *, rpl_dodag_t *);
 static void reset(rpl_dodag_t *);
 static uint16_t calc_path_cost(rpl_parent_t *parent);
 
-uint16_t cur_min_path_cost = MAX_PATH_COST;
-rpl_parent_t *cur_preferred_parent = NULL;
+static uint16_t cur_min_path_cost = MAX_PATH_COST;
+static rpl_parent_t *cur_preferred_parent = NULL;
 
-rpl_of_t rpl_of_mrhof = {
+static rpl_of_t rpl_of_mrhof = {
     0x1,
     calc_rank,
     which_parent,
diff --git a/sys/net/routing/rpl/rpl.c b/sys/net/routing/rpl/rpl.c
index 0b24bb9dba..27d2d13970 100644
--- a/sys/net/routing/rpl/rpl.c
+++ b/sys/net/routing/rpl/rpl.c
@@ -62,18 +62,18 @@ static void _dao_handle_send(rpl_dodag_t *dodag);
 static void _rpl_update_routing_table(void);
 
 #if RPL_DEFAULT_MOP == RPL_NON_STORING_MODE
-uint8_t srh_buffer[BUFFER_SIZE];
-uint8_t srh_send_buffer[BUFFER_SIZE];
-ipv6_addr_t *down_next_hop;
-ipv6_srh_t *srh_header;
-msg_t srh_m_send, srh_m_recv;
+static uint8_t srh_buffer[BUFFER_SIZE];
+static uint8_t srh_send_buffer[BUFFER_SIZE];
+static ipv6_addr_t *down_next_hop;
+static ipv6_srh_t *srh_header;
+static msg_t srh_m_send, srh_m_recv;
 #endif
 
 #if RPL_MAX_ROUTING_ENTRIES != 0
-rpl_routing_entry_t rpl_routing_table[RPL_MAX_ROUTING_ENTRIES];
+static rpl_routing_entry_t rpl_routing_table[RPL_MAX_ROUTING_ENTRIES];
 #endif
 uint8_t rpl_max_routing_entries;
-ipv6_addr_t my_address;
+static ipv6_addr_t my_address;
 
 /* IPv6 message buffer */
 static ipv6_hdr_t *ipv6_buf;
diff --git a/sys/net/routing/rpl/rpl_dodag.c b/sys/net/routing/rpl/rpl_dodag.c
index 630e2d97f6..3a6b8896ea 100644
--- a/sys/net/routing/rpl/rpl_dodag.c
+++ b/sys/net/routing/rpl/rpl_dodag.c
@@ -31,9 +31,9 @@ char addr_str[IPV6_MAX_ADDR_STR_LEN];
 #endif
 #include "debug.h"
 
-rpl_instance_t instances[RPL_MAX_INSTANCES];
-rpl_dodag_t dodags[RPL_MAX_DODAGS];
-rpl_parent_t parents[RPL_MAX_PARENTS];
+static rpl_instance_t instances[RPL_MAX_INSTANCES];
+static rpl_dodag_t dodags[RPL_MAX_DODAGS];
+static rpl_parent_t parents[RPL_MAX_PARENTS];
 
 void rpl_trickle_send_dio(void *args) {
     (void) args;
diff --git a/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c b/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
index d7a4884437..503334de72 100644
--- a/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
+++ b/sys/net/routing/rpl/rpl_nonstoring/rpl_nonstoring.c
@@ -27,7 +27,7 @@
 
 #define ENABLE_DEBUG    (0)
 #if ENABLE_DEBUG
-char addr_str_mode[IPV6_MAX_ADDR_STR_LEN];
+static char addr_str_mode[IPV6_MAX_ADDR_STR_LEN];
 #endif
 #include "debug.h"
 
diff --git a/sys/net/routing/rpl/rpl_of_manager.c b/sys/net/routing/rpl/rpl_of_manager.c
index a45a026d2f..d60944d5d8 100644
--- a/sys/net/routing/rpl/rpl_of_manager.c
+++ b/sys/net/routing/rpl/rpl_of_manager.c
@@ -29,7 +29,7 @@
 #define ENABLE_DEBUG (0)
 #include "debug.h"
 
-rpl_of_t *objective_functions[NUMBER_IMPLEMENTED_OFS];
+static rpl_of_t *objective_functions[NUMBER_IMPLEMENTED_OFS];
 
 void rpl_of_manager_init(ipv6_addr_t *my_address)
 {
diff --git a/sys/net/routing/rpl/rpl_storing/rpl_storing.c b/sys/net/routing/rpl/rpl_storing/rpl_storing.c
index 4d09e8433f..2afc8f5f1c 100644
--- a/sys/net/routing/rpl/rpl_storing/rpl_storing.c
+++ b/sys/net/routing/rpl/rpl_storing/rpl_storing.c
@@ -28,7 +28,7 @@
 
 #define ENABLE_DEBUG    (0)
 #if ENABLE_DEBUG
-char addr_str_mode[IPV6_MAX_ADDR_STR_LEN];
+static char addr_str_mode[IPV6_MAX_ADDR_STR_LEN];
 #endif
 #include "debug.h"