diff --git a/net/nat/nat.c b/net/nat/nat.c
index 4ccc2d9700b..426a04cd848 100644
--- a/net/nat/nat.c
+++ b/net/nat/nat.c
@@ -42,7 +42,7 @@
  * Private Data
  ****************************************************************************/
 
-static mutex_t g_nat_lock = NXMUTEX_INITIALIZER;
+static rmutex_t g_nat_lock = NXRMUTEX_INITIALIZER;
 
 /****************************************************************************
  * Private Functions
@@ -418,7 +418,7 @@ uint32_t nat_expire_time(uint8_t protocol)
 
 void nat_lock(void)
 {
-  nxmutex_lock(&g_nat_lock);
+  nxrmutex_lock(&g_nat_lock);
 }
 
 /****************************************************************************
@@ -431,7 +431,7 @@ void nat_lock(void)
 
 void nat_unlock(void)
 {
-  nxmutex_unlock(&g_nat_lock);
+  nxrmutex_unlock(&g_nat_lock);
 }
 
 #endif /* CONFIG_NET_NAT */