diff --git a/korman/exporter/material.py b/korman/exporter/material.py
index 5214786..1d9df22 100644
--- a/korman/exporter/material.py
+++ b/korman/exporter/material.py
@@ -701,6 +701,8 @@ class MaterialConverter:
             layer.texture = pl_env.key
 
     def export_cubic_env(self, bo, layer, texture):
+        if texture.image is None:
+            raise ExportError(f"CubeMap '{texture.name}' has no cube image!")
         width, height = texture.image.size
 
         # Sanity check: the image here should be 3x2 faces, so we should not have any