diff --git a/libavformat/au.c b/libavformat/au.c
index 6326de6f51..9e84c9d313 100644
--- a/libavformat/au.c
+++ b/libavformat/au.c
@@ -32,7 +32,7 @@
 #include "riff.h"
 
 /* if we don't know the size in advance */
-#define AU_UNKOWN_SIZE ((uint32_t)(~0))
+#define AU_UNKNOWN_SIZE ((uint32_t)(~0))
 
 /* The ffmpeg codecs we support, and the IDs they have in the file */
 static const AVCodecTag codec_au_tags[] = {
@@ -50,7 +50,7 @@ static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
         return -1;
     put_tag(pb, ".snd");       /* magic number */
     put_be32(pb, 24);           /* header size */
-    put_be32(pb, AU_UNKOWN_SIZE); /* data size */
+    put_be32(pb, AU_UNKNOWN_SIZE); /* data size */
     put_be32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
     put_be32(pb, enc->sample_rate);
     put_be32(pb, (uint32_t)enc->channels);
diff --git a/libavformat/sol.c b/libavformat/sol.c
index 8c2ea4340e..951ec6eb9a 100644
--- a/libavformat/sol.c
+++ b/libavformat/sol.c
@@ -29,7 +29,7 @@
 #include "bswap.h"
 
 /* if we don't know the size in advance */
-#define AU_UNKOWN_SIZE ((uint32_t)(~0))
+#define AU_UNKNOWN_SIZE ((uint32_t)(~0))
 
 static int sol_probe(AVProbeData *p)
 {