1 files changed, 5 insertions, 0 deletions

diff --git a/lib/libc/stdio/ungetc.3 b/lib/libc/stdio/ungetc.3
index 83483be04ffb..054213c0d234 100644
--- a/lib/libc/stdio/ungetc.3
+++ b/lib/libc/stdio/ungetc.3
@@ -73,6 +73,11 @@ an effectively infinite amount of pushback is allowed.
 .Pp
 If a character is successfully pushed-back,
 the end-of-file indicator for the stream is cleared.
+The file-position indicator is decremented
+by each successful call to
+.Fn ungetc ;
+if its value was 0 before a call, its value is unspecified after
+the call.
 .Sh RETURN VALUES
 The
 .Fn ungetc