diff --git a/control/json/zone.cpp b/control/json/zone.cpp
index d7d1a90..8053a16 100644
--- a/control/json/zone.cpp
+++ b/control/json/zone.cpp
@@ -215,6 +215,18 @@
     }
 }
 
+bool Zone::isPersisted(const std::string& intf, const std::string& prop) const
+{
+    auto it = _propsPersisted.find(intf);
+    if (it == _propsPersisted.end())
+    {
+        return false;
+    }
+
+    return std::any_of(it->second.begin(), it->second.end(),
+                       [&prop](const auto& p) { return prop == p; });
+}
+
 std::string Zone::current(std::string value)
 {
     auto current = ThermalObject::current();
@@ -359,18 +371,6 @@
     }
 }
 
-bool Zone::isPersisted(const std::string& intf, const std::string& prop)
-{
-    auto it = _propsPersisted.find(intf);
-    if (it == _propsPersisted.end())
-    {
-        return false;
-    }
-
-    return std::any_of(it->second.begin(), it->second.end(),
-                       [&prop](const auto& p) { return prop == p; });
-}
-
 void Zone::saveCurrentMode()
 {
     fs::path path{CONTROL_PERSIST_ROOT_PATH};