diff --git a/src/dj.c b/src/dj.c
index 1d12844..cb8b1db 100644
--- a/src/dj.c
+++ b/src/dj.c
@@ -118,7 +118,7 @@ oserr(char *e, int n) {
 
 /* Prints statistics regarding the use of dj, particularly partially and
  * completely read and written records. */
-static void
+static int
 fprintio(FILE *stream, char *fmt, struct Io io[2]) {
 	return fprintf(
 		stream,