diff --git a/gprMax/user_objects/user_objects.py b/gprMax/user_objects/user_objects.py
index c46ca170..9e84d032 100644
--- a/gprMax/user_objects/user_objects.py
+++ b/gprMax/user_objects/user_objects.py
@@ -134,6 +134,10 @@ class GridUserObject(MultiUserObject):
 class OutputUserObject(MultiUserObject):
     """User defined object that controls the output of data."""
 
+    @abstractmethod
+    def build(self, model: Model, grid: FDTDGrid):
+        pass
+
     def grid_name(self, grid: FDTDGrid) -> str:
         """Format grid name for use with logging info.
 
@@ -150,10 +154,6 @@ class OutputUserObject(MultiUserObject):
         else:
             return ""
 
-    @abstractmethod
-    def build(self, model: Model, grid: FDTDGrid):
-        pass
-
 
 class GeometryUserObject(GridUserObject):
     """User defined object that adds geometry to a grid."""