diff --git a/src/or/channel.c b/src/or/channel.c
index 94cca5caf8..ec44cce427 100644
--- a/src/or/channel.c
+++ b/src/or/channel.c
@@ -3450,8 +3450,8 @@ chan_cell_queue_len(const chan_cell_queue_t *queue)
  * Dump statistics for one channel to the log
  */
 
-void
-channel_dump_statistics(channel_t *chan, int severity)
+MOCK_IMPL(void,
+channel_dump_statistics, (channel_t *chan, int severity))
 {
   double avg, interval, age;
   time_t now = time(NULL);
diff --git a/src/or/channel.h b/src/or/channel.h
index ba6d66b350..07a66ebcda 100644
--- a/src/or/channel.h
+++ b/src/or/channel.h
@@ -506,7 +506,7 @@ channel_t * channel_next_with_digest(channel_t *chan);
  */
 
 const char * channel_describe_transport(channel_t *chan);
-void channel_dump_statistics(channel_t *chan, int severity);
+MOCK_DECL(void, channel_dump_statistics, (channel_t *chan, int severity));
 void channel_dump_transport_statistics(channel_t *chan, int severity);
 const char * channel_get_actual_remote_descr(channel_t *chan);
 const char * channel_get_actual_remote_address(channel_t *chan);