diff --git a/src/or/rephist.h b/src/or/rephist.h
index d2f6c66df7..303cd74f7a 100644
--- a/src/or/rephist.h
+++ b/src/or/rephist.h
@@ -117,7 +117,7 @@ extern uint32_t rephist_total_num;
 #ifdef TOR_UNIT_TESTS
 extern int onion_handshakes_requested[MAX_ONION_HANDSHAKE_TYPE+1];
 extern int onion_handshakes_assigned[MAX_ONION_HANDSHAKE_TYPE+1];
-extern bw_array_t *write_array;
+extern struct bw_array_t *write_array;
 #endif
 
 #endif