diff --git a/lib/redistat/buffer.rb b/lib/redistat/buffer.rb
index 0caa508..66e4f3c 100644
--- a/lib/redistat/buffer.rb
+++ b/lib/redistat/buffer.rb
@@ -9,9 +9,16 @@ module Redistat
     end
     
     def size
-      @size ||= 0
+      synchronize do
+        @size ||= 0
+      end
+    end
+    
+    def size=(value)
+      synchronize do
+        @size = value
+      end
     end
-    attr_writer :size
     
     def count
       @count ||= 0