diff --git a/src/theme-manager.coffee b/src/theme-manager.coffee
index b6a0e9237..3a2029915 100644
--- a/src/theme-manager.coffee
+++ b/src/theme-manager.coffee
@@ -110,6 +110,7 @@ class ThemeManager
   #Private:
   unwatchUserStylesheet: ->
     @userStylesheetFile?.off()
+    @userStylesheetFile = null
     @removeStylesheet(@userStylesheetPath) if @userStylesheetPath?
 
   # Private: