diff --git a/cmd-run-shell.c b/cmd-run-shell.c
index db5774d2..560eface 100644
--- a/cmd-run-shell.c
+++ b/cmd-run-shell.c
@@ -84,7 +84,7 @@ cmd_run_shell_print(struct job *job, const char *msg)
 
 	if (cdata->wp_id != -1)
 		wp = window_pane_find_by_id(cdata->wp_id);
-	if (wp == NULL && cdata->item != NULL)
+	if (wp == NULL && cdata->item != NULL && cdata->client != NULL)
 		wp = server_client_get_pane(cdata->client);
 	if (wp == NULL && cmd_find_from_nothing(&fs, 0) == 0)
 		wp = fs.wp;
diff --git a/cmd-set-buffer.c b/cmd-set-buffer.c
index 9112683f..c9ffe5ed 100644
--- a/cmd-set-buffer.c
+++ b/cmd-set-buffer.c
@@ -69,8 +69,13 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 		pb = paste_get_name(bufname);
 
 	if (cmd_get_entry(self) == &cmd_delete_buffer_entry) {
-		if (pb == NULL)
+		if (pb == NULL) {
+			if (bufname != NULL) {
+				cmdq_error(item, "unknown buffer: %s", bufname);
+				return (CMD_RETURN_ERROR);
+			}
 			pb = paste_get_top(&bufname);
+		}
 		if (pb == NULL) {
 			cmdq_error(item, "no buffer");
 			return (CMD_RETURN_ERROR);
@@ -80,8 +85,13 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 	}
 
 	if (args_has(args, 'n')) {
-		if (pb == NULL)
+		if (pb == NULL) {
+			if (bufname != NULL) {
+				cmdq_error(item, "unknown buffer: %s", bufname);
+				return (CMD_RETURN_ERROR);
+			}
 			pb = paste_get_top(&bufname);
+		}
 		if (pb == NULL) {
 			cmdq_error(item, "no buffer");
 			return (CMD_RETURN_ERROR);