diff --git a/tofu/data/_class05_legacy.py b/tofu/data/_class05_legacy.py
index bb66325f3..ae95f108e 100644
--- a/tofu/data/_class05_legacy.py
+++ b/tofu/data/_class05_legacy.py
@@ -111,6 +111,23 @@ def _check(
                 f"Arg cryst must be a valid .npz file, loadable!\n{error}"
             )
             raise Exception(msg)
+    elif isinstance(cryst, dict):
+        if cryst.dmat is None:
+            msg = (
+                f"Arg cryst must have a valid dmat dict, loadable!\n{error}"
+            )
+            raise Exception(msg)
+        elif cryst.dgeom is None:
+            msg = (
+                f"Arg cryst must have a valid dgeom dict, loadable!\n{error}"
+            )
+            raise Exception(msg)
+        elif cryst.dbragg is None:
+            msg = (
+                f"Arg cryst must have a valid dbragg dict, loadable!\n{error}"
+            )
+            raise Exception(msg)
+
 
     # check class
     if not cryst.__class__.__name__ == 'CrystalBragg':
@@ -222,4 +239,4 @@ def _extract_dmat(cryst):
             'power_ratio': cryst._dbragg['rockingcurve']['value'],
         }
 
-    return dmat
\ No newline at end of file
+    return dmat