diff --git a/cal_tools/cal_tools/agipdlib.py b/cal_tools/cal_tools/agipdlib.py
index 25df1619293f0d6461b6061bde489d877a50671b..1b4b976d678353202ed70946459282f8afc18a05 100644
--- a/cal_tools/cal_tools/agipdlib.py
+++ b/cal_tools/cal_tools/agipdlib.py
@@ -58,10 +58,10 @@ def get_acq_rate(fast_paths: Tuple[str, str, int],
         with h5py.File(slow_data_file, "r") as fin:
             if slow_data_path in fin:
                 # The acquisition rate value is stored in a 1D array of type
-                # float. Use the 3rd value, arbitrarily chosen. It's okay to
-                # loose precision here because the usage is about defining the
-                # rate for meta-data.
-                return round(fin[slow_data_path][3], 1)
+                # float. Use the 3rd value, arbitrarily chosen.
+                # It is desired to loose precision here because the usage is
+                # about bucketing the rate for managing meta-data.
+                return round(float(fin[slow_data_path][3]), 1)
 
     # Compute acquisition rate from fast data
     fast_data_file, karabo_id, module = fast_paths