diff --git a/sync-files/README.md b/sync-files/README.md
index 832d448a..cbcd9c23 100644
--- a/sync-files/README.md
+++ b/sync-files/README.md
@@ -57,6 +57,7 @@ The specifications are:
 | --------------------- | -------- | -------------------------------------------- | ---------------------------------------------------------------------------------------- |
 | repository            | true     | -                                            | The target repository.                                                                   |
 | ref                   | false    | The default branch of the target repository. | The version of the target repository.                                                    |
+| source-dir            | false    | Not prefixed.                                | The prefix common to `files/source`. This does not apply to the default of `files/dest`. |
 | files/source          | true     | -                                            | The path to the file in the target repository.                                           |
 | files/dest            | false    | The same as `files/source`.                  | The path where to place the synced file in the base repository.                          |
 | files/replace         | false    | `true`                                       | Whether to replace the synced file if it already exists.                                 |
diff --git a/sync-files/parse_config.py b/sync-files/parse_config.py
index a0a7cd0c..cb65ab3f 100644
--- a/sync-files/parse_config.py
+++ b/sync-files/parse_config.py
@@ -1,4 +1,5 @@
 import argparse
+import os
 import re
 from pathlib import Path
 
@@ -42,6 +43,9 @@ def main():
             if "post-commands" not in item:
                 item["post-commands"] = ""
 
+            if "source-dir" in repo_config:
+                item["source"] = os.path.join(repo_config["source-dir"], item["source"])
+
     print(yaml.dump(config))