diff --git a/cadquery/occ_impl/exporters/dxf.py b/cadquery/occ_impl/exporters/dxf.py
index 41ae15224..b806df9b2 100644
--- a/cadquery/occ_impl/exporters/dxf.py
+++ b/cadquery/occ_impl/exporters/dxf.py
@@ -1,5 +1,6 @@
 """DXF export utilities."""
 
+import warnings
 from typing import (
     Any,
     Dict,
@@ -244,6 +245,13 @@ def _dxf_circle(edge: Edge) -> DxfEntityAttributes:
         direction_y = circ.YAxis().Direction()
         direction_z = circ.Axis().Direction()
 
+        # DXF circle does not support tilted 3D circles.
+        dz = gp_Dir(0, 0, 1)
+        if abs(RAD2DEG * direction_z.Angle(dz)) % 180 > 1e-6:
+            warnings.warn(
+                "Circle not coplanar. This will fail in the future.",
+            )
+
         dy = gp_Dir(0, 1, 0)
 
         phi = direction_y.AngleWithRef(dy, direction_z)