diff --git a/whylabs_toolkit/monitor/diagnoser/converters/granularity.py b/whylabs_toolkit/monitor/diagnoser/converters/granularity.py
index 27bdd7c..a501d05 100644
--- a/whylabs_toolkit/monitor/diagnoser/converters/granularity.py
+++ b/whylabs_toolkit/monitor/diagnoser/converters/granularity.py
@@ -24,4 +24,5 @@ def calculate_num_batches(interval: str, granularity: str) -> int:
     else:
         raise ValueError(f"Unsupported granularity: {granularity}")
 
-    return floor(difference)
+    diff_as_int: int = floor(difference)
+    return diff_as_int