diff --git a/lib/notmuch.h b/lib/notmuch.h
index 9b5046b4..7e8e162d 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -814,19 +814,24 @@ notmuch_query_add_tag_exclude (notmuch_query_t *query, const char *tag);
  * notmuch_threads_destroy function, but there's no good reason
  * to call it if the query is about to be destroyed).
  *
- * If a Xapian exception occurs this function will return NULL.
- * For better error reporting, use the _st variant.
- */
-notmuch_threads_t *
-notmuch_query_search_threads (notmuch_query_t *query);
-
-/**
- * Like notmuch_query_search_threads, but with a status return.
  */
 notmuch_status_t
 notmuch_query_search_threads_st (notmuch_query_t *query,
 				 notmuch_threads_t **out);
 
+/**
+ * Like notmuch_query_search_threads_st, but without a status return.
+ *
+ * If a Xapian exception occurs this function will return NULL.
+ *
+ * @deprecated Deprecated as of libnotmuch 4.3 (notmuch 0.21). Please
+ * use notmuch_query_search_threads_st instead.
+ *
+ */
+NOTMUCH_DEPRECATED(4,3)
+notmuch_threads_t *
+notmuch_query_search_threads (notmuch_query_t *query);
+
 /**
  * Execute a query for messages, returning a notmuch_messages_t object
  * which can be used to iterate over the results. The returned
@@ -865,17 +870,23 @@ notmuch_query_search_threads_st (notmuch_query_t *query,
  * reason to call it if the query is about to be destroyed).
  *
  * If a Xapian exception occurs this function will return NULL.
- * For better error reporting, use the _st variant.
- */
-notmuch_messages_t *
-notmuch_query_search_messages (notmuch_query_t *query);
-
-/**
- * Like notmuch_query_search_messages, but with a status return.
+ *
  */
 notmuch_status_t
 notmuch_query_search_messages_st (notmuch_query_t *query,
 				  notmuch_messages_t **out);
+/**
+ * Like notmuch_query_search_messages, but without a status return.
+ *
+ * If a Xapian exception occurs this function will return NULL.
+ *
+ * @deprecated Deprecated as of libnotmuch 4.3 (notmuch 0.21). Please use
+ * notmuch_query_search_messages_st instead.
+ *
+ */
+NOTMUCH_DEPRECATED(4,3)
+notmuch_messages_t *
+notmuch_query_search_messages (notmuch_query_t *query);
 
 /**
  * Destroy a notmuch_query_t along with any associated resources.