diff --git a/docs/development/application-registry.md b/docs/development/application-registry.md
index 8d36ccf96..9503f8ff0 100644
--- a/docs/development/application-registry.md
+++ b/docs/development/application-registry.md
@@ -20,6 +20,10 @@ A dictionary mapping data backend types to their respective classes. These are u
 
 Stores registration made using `netbox.denormalized.register()`. For each model, a list of related models and their field mappings is maintained to facilitate automatic updates.
 
+### `filtersets`
+
+A dictionary mapping each model (identified by its app and label) to its filterset class, if one has been registered for it. Filtersets are registered using the `@register_filterset` decorator.
+
 ### `model_features`
 
 A dictionary of model features (e.g. custom fields, tags, etc.) mapped to the functions used to qualify a model as supporting each feature. Model features are registered using the `register_model_feature()` function in `netbox.utils`.