diff --git a/ppn2ocr b/ppn2ocr
index cbd0030..b43e227 100755
--- a/ppn2ocr
+++ b/ppn2ocr
@@ -11,8 +11,8 @@ from copy import deepcopy
 
 
 XMLNS = {
-   'mets': 'http://www.loc.gov/METS/',
-   'xlink': 'http://www.w3.org/1999/xlink'
+    'mets': 'http://www.loc.gov/METS/',
+    'xlink': 'http://www.w3.org/1999/xlink'
 }
 API_URL = 'https://oai.sbb.berlin'
 IDENTIFIER_TEMPLATE = 'oai:digital.staatsbibliothek-berlin.de:%s'
@@ -93,8 +93,8 @@ def prune_file_grps(mets):
     wanted_file_grps = ["MAX", "FULLTEXT"]
 
     for u in mets.xpath('//mets:fileGrp/@USE', namespaces=XMLNS):
-       if u not in wanted_file_grps:
-          remove_file_grp(mets, u)
+        if u not in wanted_file_grps:
+            remove_file_grp(mets, u)
 
 
 def make_workspace(ppn, workspace):
@@ -115,7 +115,7 @@ def make_workspace(ppn, workspace):
     file_grp_default = mets.find('//mets:fileGrp[@USE="DEFAULT"]', namespaces=XMLNS)
 
     if file_grp_default is None:
-         raise ValueError("This document has no DEFAULT file group, could be a multi-volume work")
+        raise ValueError("This document has no DEFAULT file group, could be a multi-volume work")
 
     file_grp_best = deepcopy(file_grp_default)