diff --git a/src/lib/libc/string/strspn.3 b/src/lib/libc/string/strspn.3
index 7d15470d..f8834dfe 100644
--- a/src/lib/libc/string/strspn.3
+++ b/src/lib/libc/string/strspn.3
@@ -33,7 +33,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: strspn.3,v 1.3 1996/08/19 08:34:25 tholo Exp $
+.\"	$OpenBSD: strspn.3,v 1.4 1999/06/04 16:30:01 aaron Exp $
 .\"
 .Dd June 29, 1991
 .Dt STRSPN 3
@@ -60,6 +60,20 @@ The
 .Fn strspn
 function
 returns the number of characters spanned.
+.Sh EXAMPLES
+The following call to
+.Fn strspn
+will return 3, since the first three characters of string
+.Fa s
+are part of string
+.Fa charset :
+.Bd -literal -offset indent
+char *s = "foobar";
+char *charset = "of";
+size_t span;
+
+span = strspn(s, charset);
+.Ed
 .Sh SEE ALSO
 .Xr index 3 ,
 .Xr memchr 3 ,