diff --git a/lib/rggen/core/builder/layer.rb b/lib/rggen/core/builder/layer.rb
index d3e291b..0571326 100644
--- a/lib/rggen/core/builder/layer.rb
+++ b/lib/rggen/core/builder/layer.rb
@@ -42,7 +42,7 @@ def execution_args(layer)
               args <<
                 if key != :use_shared_context
                   @proxy_config[key]
-                elsif @proxy_config
+                elsif @proxy_config[key]
                   layer.shared_context
                 end
             end