diff --git a/libass/ass.c b/libass/ass.c
index 711d3c52af..8022dfc9be 100644
--- a/libass/ass.c
+++ b/libass/ass.c
@@ -1021,7 +1021,7 @@ ass_track_t* ass_read_memory(ass_library_t* library, char* buf, size_t bufsize,
 	return track;
 }
 
-char* read_file_recode(char* fname, char* codepage, int* size)
+char* read_file_recode(char* fname, char* codepage, size_t* size)
 {
 	char* buf;
 	size_t bufsize;
diff --git a/libass/ass.h b/libass/ass.h
index 7eccbe9552..4bdea3a4aa 100644
--- a/libass/ass.h
+++ b/libass/ass.h
@@ -179,7 +179,7 @@ void ass_process_codec_private(ass_track_t* track, char *data, int size);
 */
 void ass_process_chunk(ass_track_t* track, char *data, int size, long long timecode, long long duration);
 
-char* read_file_recode(char* fname, char* codepage, int* size);
+char* read_file_recode(char* fname, char* codepage, size_t* size);
 
 /**
  * \brief Read subtitles from file.