diff --git a/dandischema/metadata.py b/dandischema/metadata.py
index b427169..0bd4b3e 100644
--- a/dandischema/metadata.py
+++ b/dandischema/metadata.py
@@ -320,8 +320,9 @@ def migrate(
     if instance_ver not in ALLOWED_INPUT_SCHEMAS:
         msg = (
             f"The DANDI schema version of the provided Dandiset metadata instance, "
-            f"{instance_ver!r}, is not one of the supported versions for input Dandiset"
-            f" metadata instances. The supported versions are {ALLOWED_INPUT_SCHEMAS}."
+            f"{instance_ver!r}, is not one of the supported versions for input "
+            f"Dandiset metadata instances. The supported versions are "
+            f"{ALLOWED_INPUT_SCHEMAS}."
         )
         raise ValueError(msg)
     # ----------------------------------------------------------------