--- a/algodai_reality_gap_fixture.py
+++ b/algodai_reality_gap_fixture.py
@@ -10,7 +10,7 @@
         self._timestamps = deque()
 
     def allow(self, now: float) -> bool:
-        while self._timestamps and self._timestamps[0] - now > self.window_seconds:
+        while self._timestamps and now - self._timestamps[0] >= self.window_seconds:
             self._timestamps.popleft()
         if len(self._timestamps) < self.max_requests:
             self._timestamps.append(now)