diff --git a/src/processor_base.h b/src/processor_base.h
index fb828e8c4cadffd926dc5fa971e321302d80610d..f909104cb5a921fbad61995d15e22a2695ed9000 100644
--- a/src/processor_base.h
+++ b/src/processor_base.h
@@ -33,8 +33,8 @@ class ProcessorBase : public NodeBase, public std::enable_shared_from_this<Proce
     private:
         SensorBaseWPtr sensor_ptr_;
 
-        static unsigned int processor_id_count_;
         bool is_removing_; ///< A flag for safely removing nodes from the Wolf tree. See remove().
+        static unsigned int processor_id_count_;
 
     public:
         ProcessorBase(const std::string& _type, const Scalar& _time_tolerance = 0);