diff --git a/klippy/extras/bme280.py b/klippy/extras/bme280.py
index f6a17179..0cd9f392 100644
--- a/klippy/extras/bme280.py
+++ b/klippy/extras/bme280.py
@@ -437,7 +437,7 @@ class BME280:
         else:
             factor = 0
             while duration_ms > 0x3F:
-                duration_ms /= 4
+                duration_ms //= 4
                 factor += 1
             duration_reg = duration_ms + (factor * 64)