diff --git a/km3io/daq.py b/km3io/daq.py
index be6246971fa8fbfe0efe982272cea10b8bd752c3..b3ec32291ab1fed955c3a5fb8146b6f68ca3e155 100644
--- a/km3io/daq.py
+++ b/km3io/daq.py
@@ -62,7 +62,7 @@ def get_udp_max_sequence_number(value):
 
 def has_udp_trailer(value):
     """Returns the UDP Trailer flag (fifo)"""
-    return np.any(np.bitwise_and(value, np.leftshift(1, 31)))
+    return np.any(np.bitwise_and(value, np.left_shift(1, 31)))
 
 
 class DAQReader: