diff --git a/hamilflow/models/d1/harmonic_oscillator_chain.py b/hamilflow/models/d1/harmonic_oscillator_chain.py
index 4efbd6f..7e15d0a 100644
--- a/hamilflow/models/d1/harmonic_oscillator_chain.py
+++ b/hamilflow/models/d1/harmonic_oscillator_chain.py
@@ -81,7 +81,7 @@ def _x(self, t: ArrayLike) -> tuple[ArrayLike, ArrayLike]:
             t = np.asarray([t])
         travelling_waves = np.asarray([tw._x(t) for tw in self.travelling_waves])
         # FIXME this is imaginary
-        original_xs = ifft(travelling_waves.T, norm="ortho").T
+        original_xs = ifft(travelling_waves, axis=0, norm="ortho")
 
         return original_xs, travelling_waves