diff --git a/src/grammar-registry.coffee b/src/grammar-registry.coffee
index 1437e6a96..109e719fc 100644
--- a/src/grammar-registry.coffee
+++ b/src/grammar-registry.coffee
@@ -135,5 +135,4 @@ class GrammarRegistry extends FirstMate.GrammarRegistry
     undefined
 
   clearObservers: ->
-    @off() if includeDeprecatedAPIs
     @emitter = new Emitter