diff --git a/src/netconf-client.cpp b/src/netconf-client.cpp
index fde9561..c09a2db 100644
--- a/src/netconf-client.cpp
+++ b/src/netconf-client.cpp
@@ -75,7 +75,7 @@
 }
 
 template <typename Type> using deleter_type_for = void (*)(Type*);
-template <typename Type> deleter_type_for<Type> deleter_for;
+template <typename Type> deleter_type_for<Type> const deleter_for;
 
 template <> const auto deleter_for<nc_rpc> = nc_rpc_free;
 template <> const auto deleter_for<nc_reply> = nc_reply_free;