diff --git a/src/filescanner_ffmpeg.c b/src/filescanner_ffmpeg.c
index 6ea25421..e5103aae 100644
--- a/src/filescanner_ffmpeg.c
+++ b/src/filescanner_ffmpeg.c
@@ -51,7 +51,7 @@ struct metadata_map {
 static char errbuf[64];
 
 static inline char *
-err2str(errnum)
+err2str(int errnum)
 {
   av_strerror(errnum, errbuf, sizeof(errbuf));
   return errbuf;
diff --git a/src/transcode.c b/src/transcode.c
index 44f60767..b6ee21bb 100644
--- a/src/transcode.c
+++ b/src/transcode.c
@@ -197,7 +197,7 @@ init_profile(struct encode_ctx *ctx, enum transcode_profile profile)
 /* -------------------------------- HELPERS -------------------------------- */
 
 static inline char *
-err2str(errnum)
+err2str(int errnum)
 {
   av_strerror(errnum, errbuf, sizeof(errbuf));
   return errbuf;