diff --git a/src/calibre/ebooks/txt/processor.py b/src/calibre/ebooks/txt/processor.py
index afeb93bc1f..3f427d1f37 100644
--- a/src/calibre/ebooks/txt/processor.py
+++ b/src/calibre/ebooks/txt/processor.py
@@ -220,7 +220,7 @@ def remove_indents(txt):
     '''
     Remove whitespace at the beginning of each line.
     '''
-    return re.sub(r'^\s+', '', txt, flags=re.MULTILINE)
+    return re.sub(r'^[\r\t\f\v ]+', r'', txt, flags=re.MULTILINE)
 
 
 def opf_writer(path, opf_name, manifest, spine, mi):