diff --git a/paddle/fluid/framework/scope.h b/paddle/fluid/framework/scope.h
index 7f80bbc4fc8878979f8fac2d02e618b4b960c609..647972e61872b6c615a5c52b1da13234f6c29d26 100644
--- a/paddle/fluid/framework/scope.h
+++ b/paddle/fluid/framework/scope.h
@@ -49,8 +49,6 @@ class ScopeBase {
   virtual ~ScopeBase() {}
 };
 
-class Scope;
-
 /**
  * @brief Scope that manage all variables.
  *