diff --git a/CHANGELOG b/CHANGELOG
index e885d42f82..378b5c5798 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -10,6 +10,10 @@ git-annex (6.20170819) UNRELEASED; urgency=medium
   * init: Display an additional message when it detects a filesystem that
     allows writing to files whose write bit is not set.
   * S3: Allow removing files from IA.
+  * webdav: Checking if a non-existent file is present on Box.com
+    triggered a bug in its webdav support that generates an infinite series
+    of redirects. Deal with such problems by assuming such behavior means
+    the file is not present.
 
  -- Joey Hess <id@joeyh.name>  Mon, 28 Aug 2017 12:20:59 -0400
 
diff --git a/Remote/WebDAV.hs b/Remote/WebDAV.hs
index 04eb35cef7..12b9d40b2f 100644
--- a/Remote/WebDAV.hs
+++ b/Remote/WebDAV.hs
@@ -32,7 +32,7 @@ import Remote.Helper.Export
 import qualified Remote.Helper.Chunked.Legacy as Legacy
 import Creds
 import Utility.Metered
-import Utility.Url (URLString, matchStatusCodeException)
+import Utility.Url (URLString, matchStatusCodeException, matchHttpExceptionContent)
 import Annex.UUID
 import Remote.WebDAV.DavLocation
 
@@ -317,11 +317,15 @@ existsDAV l = inLocation l check `catchNonAsync` (\e -> return (Left $ show e))
 		-- more depth is certainly not needed to check if a
 		-- location exists.
 		setDepth (Just Depth1)
-		catchJust
-			(matchStatusCodeException (== notFound404))
+		catchJust missinghttpstatus
 			(getPropsM >> ispresent True)
 			(const $ ispresent False)
 	ispresent = return . Right
+	missinghttpstatus e = 
+		matchStatusCodeException (== notFound404) e
+		<|> matchHttpExceptionContent toomanyredirects e
+	toomanyredirects (TooManyRedirects _) = True
+	toomanyredirects _ = False
 
 safely :: DAVT IO a -> DAVT IO (Maybe a)
 safely = eitherToMaybe <$$> tryNonAsync
diff --git a/Utility/Url.hs b/Utility/Url.hs
index e1a21af5dc..e6dcd33889 100644
--- a/Utility/Url.hs
+++ b/Utility/Url.hs
@@ -27,6 +27,7 @@ module Utility.Url (
 	downloadQuiet,
 	parseURIRelaxed,
 	matchStatusCodeException,
+	matchHttpExceptionContent,
 ) where
 
 import Common
@@ -365,3 +366,9 @@ matchStatusCodeException want e@(StatusCodeException s _ _)
 	| otherwise = Nothing
 matchStatusCodeException _ _ = Nothing
 #endif
+
+matchHttpExceptionContent :: (HttpExceptionContent -> Bool) -> HttpException -> Maybe HttpException
+matchHttpExceptionContent want e@(HttpExceptionRequest _ hec)
+	| want hec = Just e
+	| otherwise = Nothing
+matchHttpExceptionContent _ _ = Nothing