diff --git a/wpa_supplicant/bss.c b/wpa_supplicant/bss.c
index 7b6ed773a..7e420485f 100644
--- a/wpa_supplicant/bss.c
+++ b/wpa_supplicant/bss.c
@@ -1359,7 +1359,7 @@ int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates)
 
 
 #ifdef CONFIG_FILS
-const u8 * wpa_bss_get_fils_cache_id(struct wpa_bss *bss)
+const u8 * wpa_bss_get_fils_cache_id(const struct wpa_bss *bss)
 {
 	const u8 *ie;
 
diff --git a/wpa_supplicant/bss.h b/wpa_supplicant/bss.h
index 071676174..e49858d19 100644
--- a/wpa_supplicant/bss.h
+++ b/wpa_supplicant/bss.h
@@ -148,7 +148,7 @@ int wpa_bss_get_max_rate(const struct wpa_bss *bss);
 int wpa_bss_get_bit_rates(const struct wpa_bss *bss, u8 **rates);
 struct wpa_bss_anqp * wpa_bss_anqp_alloc(void);
 int wpa_bss_anqp_unshare_alloc(struct wpa_bss *bss);
-const u8 * wpa_bss_get_fils_cache_id(struct wpa_bss *bss);
+const u8 * wpa_bss_get_fils_cache_id(const struct wpa_bss *bss);
 int wpa_bss_ext_capab(const struct wpa_bss *bss, unsigned int capab);
 
 static inline int bss_is_dmg(const struct wpa_bss *bss)