diff --git a/ahrs/common/quaternion.py b/ahrs/common/quaternion.py
index 9edf5bb..0b913d8 100644
--- a/ahrs/common/quaternion.py
+++ b/ahrs/common/quaternion.py
@@ -2943,7 +2943,7 @@ def rotate_by(self, q: np.ndarray, inplace: bool = False, order: str = 'H') -> n
         qQ[:, 3] = q[0]*self.z + q[1]*self.y - q[2]*self.x + q[3]*self.w
         qQ /= np.linalg.norm(qQ, axis=1)[:, None]
         if inplace:
-            self.array = qQ
+            self.array[:] = qQ
             return None
         return qQ