diff --git a/tuf/developer_tool.py b/tuf/developer_tool.py
index 685e754a42..0db06fe847 100755
--- a/tuf/developer_tool.py
+++ b/tuf/developer_tool.py
@@ -190,7 +190,7 @@ def __init__(self, project_name, metadata_directory, targets_directory,
     securesystemslib.formats.NAME_SCHEMA.check_match(project_name)
     securesystemslib.formats.PATH_SCHEMA.check_match(metadata_directory)
     securesystemslib.formats.PATH_SCHEMA.check_match(targets_directory)
-    securesystemslib.formats.PATH_SCHEMA.check_match(file_prefix)
+    securesystemslib.formats.ANY_STRING_SCHEMA.check_match(file_prefix)
     securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)
 
     self.metadata_directory = metadata_directory