diff --git a/tests/data/test_minute_bars.py b/tests/data/test_minute_bars.py
index 8418b04d..a61308a9 100644
--- a/tests/data/test_minute_bars.py
+++ b/tests/data/test_minute_bars.py
@@ -633,7 +633,7 @@ class BcolzMinuteBarTestCase(WithTradingCalendars,
                 view(float64),
                 'close': ((0b11111111111 << 52) + arange(31, 40, dtype=int64)).
                 view(float64),
-                'volume': full(9, 0),
+                'volume': full(9, 0.0),
             },
             index=[minutes])
         self.writer.write_sid(sid, data)