diff --git a/gala/potential/potential/core.py b/gala/potential/potential/core.py
index 7d0c4846..f782948d 100644
--- a/gala/potential/potential/core.py
+++ b/gala/potential/potential/core.py
@@ -757,6 +757,8 @@ def plot_rotation_curve(self, R_grid, t=0.0, ax=None, labels=None, **plot_kwargs
 
         if ax is None:
             fig, ax = plt.subplots()
+        else:
+            fig = ax.figure
 
         if labels is not False:
             ax.set_xlabel(labels[0])