diff --git a/pyrelacs/dataio/daq_producer.py b/pyrelacs/dataio/daq_producer.py
index a88c5cb..295e428 100644
--- a/pyrelacs/dataio/daq_producer.py
+++ b/pyrelacs/dataio/daq_producer.py
@@ -41,7 +41,7 @@ class DaqProducer:
         )
 
         # let the buffer for the daq device hold 5 seconds of data
-        daq_buffer_size = self.buffer.samplerate * 5
+        daq_buffer_size = int(self.buffer.samplerate * 5)
 
         data_in = uldaq.create_float_buffer(channel_range.size, daq_buffer_size)
         log.debug(f"Buffersize for daq {len(data_in)}")