diff --git a/tests/common.py b/tests/common.py
index bcb66428f6b..16f349de800 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -295,8 +295,8 @@ def async_fire_time_changed(hass, datetime_, fire_all=False):
         if task.cancelled():
             continue
 
-        future_seconds = task.when() - hass.loop.time()
         mock_seconds_into_future = datetime_.timestamp() - time.time()
+        future_seconds = task.when() - hass.loop.time()
 
         if fire_all or mock_seconds_into_future >= future_seconds:
             with patch(