diff --git a/src/nf_nat_fullcone.c b/src/nf_nat_fullcone.c
index 0757ef9..0b13cbe 100644
--- a/src/nf_nat_fullcone.c
+++ b/src/nf_nat_fullcone.c
@@ -854,7 +854,11 @@ static uint16_t find_appropriate_port6(struct net *net, const u16 zone,
 		/* for now we do the same thing for both --random and --random-fully */
 
 		/* select a random starting point */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)
+		start = (uint16_t) (get_random_u32() % (u32) range_size);
+#else
 		start = (uint16_t) (prandom_u32() % (u32) range_size);
+#endif
 	} else {
 
 		if ((original_port >= min && original_port <= min + range_size - 1)
@@ -927,7 +931,11 @@ static uint16_t find_appropriate_port(struct net *net, const u16 zone,
 		/* for now we do the same thing for both --random and --random-fully */
 
 		/* select a random starting point */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)
+		start = (uint16_t) (get_random_u32() % (u32) range_size);
+#else
 		start = (uint16_t) (prandom_u32() % (u32) range_size);
+#endif
 	} else {
 
 		if ((original_port >= min && original_port <= min + range_size - 1)