diff --git a/slow.1 b/slow.1
index 01a481c..510c55e 100644
--- a/slow.1
+++ b/slow.1
@@ -5,7 +5,7 @@ slow \- Slow down ouput
 .B slow
 .RB [ \-t
 .IR time ]
-.RB [ \-F ]
+.RB [ \-f ]
 .SH DESCRIPTION
 .B slow
 cat stdin to stdout with a usleep between each bytes.
@@ -15,7 +15,7 @@ cat stdin to stdout with a usleep between each bytes.
 specify sleep time between each bytes in micro-second.
 Default value is 1 second.
 .TP
-.B \-F
+.B \-f
 force flushing after each bytes.
 useful with buffered stdout like ttys.
 .TP
diff --git a/slow.c b/slow.c
index 541039e..9f59d4f 100644
--- a/slow.c
+++ b/slow.c
@@ -8,7 +8,7 @@
 char *argv0;
 
 void usage() {
-	fprintf(stderr, "usage: %s [-t usec] [-F]\n", argv0);
+	fprintf(stderr, "usage: %s [-t usec] [-f]\n", argv0);
 	exit(EXIT_FAILURE);
 }
 
@@ -22,7 +22,7 @@ int main(int argc, char *argv[]) {
 	case 't':
 		useconds = atoi(EARGF(usage()));
 		break;
-	case 'F':
+	case 'f':
 		flush = 1;
 		break;
 	default: