diff --git a/fvcore/common/param_scheduler.py b/fvcore/common/param_scheduler.py
index bfa3ace..3bc5e1e 100644
--- a/fvcore/common/param_scheduler.py
+++ b/fvcore/common/param_scheduler.py
@@ -56,7 +56,7 @@ def __init__(self, value: float) -> None:
         self._value = value
 
     def __call__(self, where: float) -> float:
-        if where >= 1.0:
+        if (where - self.WHERE_EPSILON) >= 1.0:
             raise RuntimeError(
                 f"where in ParamScheduler must be in [0, 1]: got {where}"
             )