diff --git a/src/utils/nat.c b/src/utils/nat.c
index a24c0f7ba..e881e45f0 100644
--- a/src/utils/nat.c
+++ b/src/utils/nat.c
@@ -60,7 +60,7 @@
 
 #define DEFAULT_ALLOCATION_TIMEOUT_S 1800
 #define MOD_NAME "[NAT] "
-#define PREALLOCATE_S 5 ///< number of seconds that repeated allocation is performed before timeout
+#define PREALLOCATE_S 30 ///< number of seconds that repeated allocation is performed before timeout
 
 struct ug_nat_traverse {
         enum traverse_t {