diff --git a/src/files.jl b/src/files.jl
index 9033cc18e4a948cd4f9d3e6fd23f1300d4da4053..2dce232a5ebe426ad9729a477edd3e358ec5107a 100644
--- a/src/files.jl
+++ b/src/files.jl
@@ -250,9 +250,12 @@ end
 getoutput(controller) = gethub(controller)[:output]
 
 function valid_filename(name)
+    if startswith(name, ".")
+        return false
+    end
     # adapted from NyxUI.jl (MIT license, same author)
     windows_extra = "|:*?<>"
-    for c in "./\\'\"`" * windows_extra
+    for c in "/\\'\"`" * windows_extra
         if c in name
             return false
         end