diff --git a/superxas_bec/devices/timepix/timepix.py b/superxas_bec/devices/timepix/timepix.py
index 9e31b40..181dd16 100644
--- a/superxas_bec/devices/timepix/timepix.py
+++ b/superxas_bec/devices/timepix/timepix.py
@@ -240,6 +240,7 @@ class Timepix(PSIDeviceBase, TimePixControl):
         AsyncSignal,
         name="spectra",
         ndim=1,
+        max_size=1000,
         acquisition_group="monitored",
         async_update={"type": "add", "max_shape": [None]},
         doc="Spectra signal of the TimePix detector.",