diff --git a/src/Simplex/Chat/Web.hs b/src/Simplex/Chat/Web.hs
index 30d674d55f..80f7432da2 100644
--- a/src/Simplex/Chat/Web.hs
+++ b/src/Simplex/Chat/Web.hs
@@ -16,6 +16,7 @@ module Simplex.Chat.Web
     webPreviewWorker,
     writeCorsConfig,
     removeStaleFiles,
+    publicGroupIdFileName,
     channelContentChanged,
     channelProfileUpdated,
     channelRemoved,
@@ -416,9 +417,11 @@ removeStaleFiles dir activeFiles = do
         let f' = if takeExtension f == ".tmp" then dropExtension f else f
             base = dropExtension f'
          in takeExtension f' == ".json" && not (null base) && all isBase64Url base
-      isBase64Url c = (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-' || c == '_'
+      isBase64Url c = (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-' || c == '_' || c == '='
   allFiles <- S.filter isPreviewFile . S.fromList <$> listDirectory dir
-  mapM_ (\f -> removeFile (dir </> f)) $ S.difference allFiles activeFiles
+  forM_ (S.difference allFiles activeFiles) $ \f ->
+    removeFile (dir </> f) `catchOwn'` \(e :: SomeException) ->
+      logError $ "web preview: error removing stale file " <> T.pack f <> ": " <> tshow e
 
 toFormattedText :: Text -> Maybe MarkdownList
 toFormattedText t = case parseMaybeMarkdownList t of
diff --git a/tests/ChatTests/ChatRelays.hs b/tests/ChatTests/ChatRelays.hs
index a30546ed91..a555fcc9ef 100644
--- a/tests/ChatTests/ChatRelays.hs
+++ b/tests/ChatTests/ChatRelays.hs
@@ -19,9 +19,10 @@ import qualified Data.Text as T
 import ProtocolTests (testGroupProfile)
 import Simplex.Chat.Controller (ChatConfig (..))
 import Simplex.Chat.Protocol (LinkOwnerSig, MsgChatLink (..), MsgContent (..))
-import Simplex.Chat.Types (GroupProfile (..))
+import Simplex.Chat.Types (B64UrlByteString (..), GroupProfile (..))
 import Simplex.Chat.Controller (CorsOrigin (..))
-import Simplex.Chat.Web (WebChannelPreview (..), WebMessage (..), extractOrigin, removeStaleFiles, writeCorsConfig)
+import Simplex.Chat.Web (WebChannelPreview (..), WebMessage (..), extractOrigin, publicGroupIdFileName, removeStaleFiles, writeCorsConfig)
+import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.BBS (bbsKeyGen)
 import Simplex.Messaging.Encoding.String (StrEncoding (..))
 import Simplex.Messaging.Util (decodeJSON)
@@ -569,8 +570,9 @@ testWebPreviewChannelDeleted ps =
 testWebPreviewStaleCleanup :: HasCallStack => TestParams -> IO ()
 testWebPreviewStaleCleanup ps = do
   let webDir = tmpPath ps </> "web_stale_unit"
-      activeFile = "abc123.json"
-      staleFile = "AAAA_stale.json"
+      previewFileName s = publicGroupIdFileName (B64UrlByteString $ C.sha256Hash s) <> ".json"
+      activeFile = previewFileName "active"
+      staleFile = previewFileName "stale"
       safeFile = "my.config.json"
   createDirectoryIfMissing True webDir
   writeFile (webDir </> activeFile) "{}"