diff --git a/app/scripts/prepare_build b/app/scripts/prepare_build
index b61f26c66c..ad96024249 100755
--- a/app/scripts/prepare_build
+++ b/app/scripts/prepare_build
@@ -118,7 +118,7 @@ def main():
             with open(os.path.join(translators_dir, fn), 'r', encoding='utf-8') as f:
                 contents = f.read()
             # Parse out the JSON metadata block
-            m = re.match('^\s*{[\S\s]*?}\s*?[\r\n]', contents)
+            m = re.match(r'^\s*{[\S\s]*?}\s*?[\r\n]', contents)
             if not m:
                 raise Exception("Metadata block not found in " + f.name)
             metadata = json.loads(m.group(0))