diff --git a/include/ieee80211.h b/include/ieee80211.h
index dde8b4c..9fb6b48 100644
--- a/include/ieee80211.h
+++ b/include/ieee80211.h
@@ -1529,18 +1529,30 @@ enum ieee80211_state {
 	(((Addr[2]) & 0xff) == 0xff) && (((Addr[3]) & 0xff) == 0xff) && (((Addr[4]) & 0xff) == 0xff) && \
 				     (((Addr[5]) & 0xff) == 0xff))
 #else
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 18, 0))
+static inline int is_multicast_mac_addr(const u8 *addr)
+#else
 extern __inline int is_multicast_mac_addr(const u8 *addr)
+#endif
 {
 	return (addr[0] != 0xff) && (0x01 & addr[0]);
 }
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 18, 0))
+static inline int is_broadcast_mac_addr(const u8 *addr)
+#else
 extern __inline int is_broadcast_mac_addr(const u8 *addr)
+#endif
 {
 	return ((addr[0] == 0xff) && (addr[1] == 0xff) && (addr[2] == 0xff) &&   \
 		(addr[3] == 0xff) && (addr[4] == 0xff) && (addr[5] == 0xff));
 }
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 18, 0))
+static inline int is_zero_mac_addr(const u8 *addr)
+#else
 extern __inline int is_zero_mac_addr(const u8 *addr)
+#endif
 {
 	return ((addr[0] == 0x00) && (addr[1] == 0x00) && (addr[2] == 0x00) &&   \
 		(addr[3] == 0x00) && (addr[4] == 0x00) && (addr[5] == 0x00));