diff --git a/nimble/host/include/host/ble_uuid.h b/nimble/host/include/host/ble_uuid.h
index a2be09541..4cfaf5362 100644
--- a/nimble/host/include/host/ble_uuid.h
+++ b/nimble/host/include/host/ble_uuid.h
@@ -99,6 +99,7 @@ typedef union {
 #define BLE_UUID128(u) \
     ((ble_uuid128_t *) (u))
 
+/** Includes trailing \0. */
 #define BLE_UUID_STR_LEN (37)
 
 int ble_uuid_init_from_buf(ble_uuid_any_t *uuid, const void *buf, size_t len);
@@ -106,6 +107,8 @@ int ble_uuid_cmp(const ble_uuid_t *uuid1, const ble_uuid_t *uuid2);
 char *ble_uuid_to_str(const ble_uuid_t *uuid, char *dst);
 uint16_t ble_uuid_u16(const ble_uuid_t *uuid);
 
+int ble_uuid_to_s(char *dst, int dst_sz, const void *uuid128);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/nimble/host/src/ble_uuid.c b/nimble/host/src/ble_uuid.c
index f9ccc6dc6..ff9487033 100644
--- a/nimble/host/src/ble_uuid.c
+++ b/nimble/host/src/ble_uuid.c
@@ -21,6 +21,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <stdio.h>
 #include "os/os_mbuf.h"
 #include "nimble/ble.h"
 #include "ble_hs_priv.h"