diff --git a/sys/src/avutil/log.rs b/sys/src/avutil/log.rs
index 6d4bfa4..83401b3 100644
--- a/sys/src/avutil/log.rs
+++ b/sys/src/avutil/log.rs
@@ -78,7 +78,7 @@ pub fn AV_LOG_C(x: c_int) -> c_int {
 }
 
 extern {
-	pub fn av_log(avcl: *mut c_void, level: c_int, fmt: *const char, ...);
+	pub fn av_log(avcl: *mut c_void, level: c_int, fmt: *const c_char, ...);
 	//pub fn av_vlog(avcl: *mut c_void, level: c_int, fmt: *const c_char, vl: va_list);
 	pub fn av_log_get_level() -> c_int;
 	pub fn av_log_set_level(level: c_int);