diff --git a/Mailnag/backends/imap.py b/Mailnag/backends/imap.py
index 91ecd66..f6e74dd 100644
--- a/Mailnag/backends/imap.py
+++ b/Mailnag/backends/imap.py
@@ -148,7 +148,7 @@ def mark_as_seen(self, mails):
 						if folder != last_folder:
 							conn.select(f'"{folder}"', readonly = False)
 							last_folder = folder
-						status, data = conn.uid("STORE", m.flags['uid'], "+FLAGS", "(\Seen)")
+						status, data = conn.uid("STORE", m.flags['uid'], "+FLAGS", r"(\Seen)")
 					except:
 						logging.warning("Failed to set mail with uid %s to seen on server (account: '%s').", m.flags['uid'], acc.name)
 
diff --git a/Mailnag/common/imaplib2.py b/Mailnag/common/imaplib2.py
index e97ccab..70fa8d3 100644
--- a/Mailnag/common/imaplib2.py
+++ b/Mailnag/common/imaplib2.py
@@ -2466,7 +2466,7 @@ def ParseFlags(resp):
     ('select', ('imaplib2_test2',)),
     ('search', (None, 'SUBJECT', '"IMAP4 test"')),
     ('fetch', ('1:*', '(FLAGS INTERNALDATE RFC822)')),
-    ('store', ('1', 'FLAGS', '(\Deleted)')),
+    ('store', ('1', 'FLAGS', r'(\Deleted)')),
     ('namespace', ()),
     ('expunge', ()),
     ('recent', ()),
@@ -2571,7 +2571,7 @@ def run(cmd, args, cb=True):
             if not uid: continue
             run('uid', ('FETCH', uid[-1],
                     '(FLAGS INTERNALDATE RFC822.SIZE RFC822.HEADER RFC822.TEXT)'))
-            run('uid', ('STORE', uid[-1], 'FLAGS', '(\Deleted)'))
+            run('uid', ('STORE', uid[-1], 'FLAGS', r'(\Deleted)'))
             run('expunge', ())
 
         if 'IDLE' in M.capabilities:
@@ -2585,10 +2585,10 @@ def run(cmd, args, cb=True):
             dat = run('fetch', (num, '(FLAGS INTERNALDATE RFC822)'), cb=False)
             M._mesg('fetch %s => %s' % (num, repr(dat)))
             run('idle', (2,))
-            run('store', (num, '-FLAGS', '(\Seen)'), cb=False),
+            run('store', (num, '-FLAGS', r'(\Seen)'), cb=False),
             dat = run('fetch', (num, '(FLAGS INTERNALDATE RFC822)'), cb=False)
             M._mesg('fetch %s => %s' % (num, repr(dat)))
-            run('uid', ('STORE', num, 'FLAGS', '(\Deleted)'))
+            run('uid', ('STORE', num, 'FLAGS', r'(\Deleted)'))
             run('expunge', ())
             if idle_intr:
                 M._mesg('HIT CTRL-C to interrupt IDLE')