diff --git a/src/or/router.c b/src/or/router.c
index edae2671f38561e8b2578293021345a699a2f513..317cef2819a1726308d305dd3988bea9119824b5 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -232,7 +232,8 @@ get_server_identity_key(void)
   return server_identitykey;
 }
 
-/** Return true iff the server identity key has been set. */
+/** Return true iff we are a server and the server identity key
+ * has been set. */
 int
 server_identity_key_is_set(void)
 {