diff --git a/tests/test_in_vterm/test_tmux.py b/tests/test_in_vterm/test_tmux.py
index 62f9487f..72fa1f94 100755
--- a/tests/test_in_vterm/test_tmux.py
+++ b/tests/test_in_vterm/test_tmux.py
@@ -73,7 +73,7 @@ def main():
 			},
 		)
 		p.start()
-		sleep(1)
+		sleep(10)
 		last_line = []
 		for col in range(cols):
 			last_line.append(p[rows - 1, col])