diff --git a/pathplannerlib-python/pathplannerlib/trajectory.py b/pathplannerlib-python/pathplannerlib/trajectory.py
index 215cc797..78fa3321 100644
--- a/pathplannerlib-python/pathplannerlib/trajectory.py
+++ b/pathplannerlib-python/pathplannerlib/trajectory.py
@@ -27,7 +27,7 @@ def __init__(self):
 @dataclass
 class PathPlannerTrajectoryState:
     timeSeconds: float = 0.0
-    fieldSpeeds: ChassisSpeeds = ChassisSpeeds()
+    fieldSpeeds: ChassisSpeeds = field(default_factory=ChassisSpeeds)
     pose: Pose2d = field(default_factory=Pose2d)
     linearVelocity: float = 0.0
     feedforwards: DriveFeedforwards = None