diff --git a/lib/ash_json_api/json_schema/open_api.ex b/lib/ash_json_api/json_schema/open_api.ex
index 38b3007..36d41fc 100644
--- a/lib/ash_json_api/json_schema/open_api.ex
+++ b/lib/ash_json_api/json_schema/open_api.ex
@@ -3039,7 +3039,8 @@ if Code.ensure_loaded?(OpenApiSpex) do
     end
 
     defp attribute_filter_field_type(resource, attribute) do
-      AshJsonApi.Resource.Info.type(resource) <> "-filter-" <> to_string(attribute.name)
+      AshJsonApi.Resource.Info.type(resource) <>
+        "-filter-" <> AshJsonApi.Resource.Info.field_to_json_key(resource, attribute.name)
     end
 
     defp resource_filter_fields(resource, domains) do
@@ -3093,7 +3094,7 @@ if Code.ensure_loaded?(OpenApiSpex) do
         |> filter_shown_fields(resource)
         |> Enum.filter(&filterable?(&1, resource))
         |> Enum.map(fn calculation ->
-          {calculation.name,
+          {AshJsonApi.Resource.Info.field_to_json_key(resource, calculation.name),
            %Reference{
              "$ref": "#/components/schemas/#{attribute_filter_field_type(resource, calculation)}"
            }}
@@ -3109,7 +3110,7 @@ if Code.ensure_loaded?(OpenApiSpex) do
       |> filter_shown_fields(resource)
       |> Enum.filter(&filterable?(&1, resource))
       |> Enum.map(fn attribute ->
-        {attribute.name,
+        {AshJsonApi.Resource.Info.field_to_json_key(resource, attribute.name),
          %Reference{
            "$ref": "#/components/schemas/#{attribute_filter_field_type(resource, attribute)}"
          }}
@@ -3123,7 +3124,7 @@ if Code.ensure_loaded?(OpenApiSpex) do
         |> filter_shown_fields(resource)
         |> Enum.filter(&filterable?(&1, resource))
         |> Enum.map(fn aggregate ->
-          {aggregate.name,
+          {AshJsonApi.Resource.Info.field_to_json_key(resource, aggregate.name),
            %Reference{
              "$ref": "#/components/schemas/#{attribute_filter_field_type(resource, aggregate)}"
            }}
diff --git a/test/acceptance/field_names_test.exs b/test/acceptance/field_names_test.exs
index 73b00d1..ee56711 100644
--- a/test/acceptance/field_names_test.exs
+++ b/test/acceptance/field_names_test.exs
@@ -737,6 +737,35 @@ defmodule Test.Acceptance.FieldNamesTest do
     end
   end
 
+  # ─── OpenAPI filter schema ────────────────────────────────────────────────────
+
+  describe "field_names – OpenAPI filter schema" do
+    test "filter properties use the renamed attribute keys" do
+      api_spec =
+        AshJsonApi.Controllers.OpenApi.spec(%{private: %{}}, domains: [Domain])
+
+      filter_schema = api_spec.components.schemas["post-filter"]
+
+      assert Map.has_key?(filter_schema.properties, "subject")
+      assert Map.has_key?(filter_schema.properties, "content")
+      refute Map.has_key?(filter_schema.properties, "title")
+      refute Map.has_key?(filter_schema.properties, "body")
+    end
+
+    test "filter property $refs and component schema ids use the renamed keys" do
+      api_spec =
+        AshJsonApi.Controllers.OpenApi.spec(%{private: %{}}, domains: [Domain])
+
+      filter_schema = api_spec.components.schemas["post-filter"]
+
+      assert filter_schema.properties["subject"]."$ref" ==
+               "#/components/schemas/post-filter-subject"
+
+      assert Map.has_key?(api_spec.components.schemas, "post-filter-subject")
+      refute Map.has_key?(api_spec.components.schemas, "post-filter-title")
+    end
+  end
+
   # ─── Sparse fieldsets ─────────────────────────────────────────────────────────
 
   describe "field_names – sparse fieldsets (fields[])" do
diff --git a/test/acceptance/open_api_test.exs b/test/acceptance/open_api_test.exs
index 210af21..50bfb2e 100644
--- a/test/acceptance/open_api_test.exs
+++ b/test/acceptance/open_api_test.exs
@@ -467,10 +467,10 @@ defmodule Test.Acceptance.OpenApiTest do
     refute Map.has_key?(relationships, :hidden_author)
 
     filter_schema = api_spec.components.schemas["hidden-spec-post-filter"]
-    assert Map.has_key?(filter_schema.properties, :name)
+    assert Map.has_key?(filter_schema.properties, "name")
     assert Map.has_key?(filter_schema.properties, :visible_author)
-    refute Map.has_key?(filter_schema.properties, :secret)
-    refute Map.has_key?(filter_schema.properties, :secret_calc)
+    refute Map.has_key?(filter_schema.properties, "secret")
+    refute Map.has_key?(filter_schema.properties, "secret_calc")
     refute Map.has_key?(filter_schema.properties, :hidden_author)
     refute Map.has_key?(api_spec.components.schemas, "hidden-spec-post-filter-secret")
     refute Map.has_key?(api_spec.components.schemas, "hidden-spec-post-filter-secret_calc")
@@ -694,35 +694,35 @@ defmodule Test.Acceptance.OpenApiTest do
                type: :deepObject,
                description: "Filters the query to results matching the given filter object",
                properties: %{
-                 author: %Reference{"$ref": "#/components/schemas/author-filter"},
-                 author_id: %Reference{
+                 :author => %Reference{"$ref": "#/components/schemas/author-filter"},
+                 "author_id" => %Reference{
                    "$ref": "#/components/schemas/post-filter-author_id"
                  },
-                 count_of_tags: %Reference{
+                 "count_of_tags" => %Reference{
                    "$ref": "#/components/schemas/post-filter-count_of_tags"
                  },
-                 email: %Reference{"$ref": "#/components/schemas/post-filter-email"},
-                 hidden: %Reference{"$ref": "#/components/schemas/post-filter-hidden"},
-                 id: %Reference{"$ref": "#/components/schemas/post-filter-id"},
-                 name: %Reference{"$ref": "#/components/schemas/post-filter-name"},
-                 and: %Schema{
+                 "email" => %Reference{"$ref": "#/components/schemas/post-filter-email"},
+                 "hidden" => %Reference{"$ref": "#/components/schemas/post-filter-hidden"},
+                 "id" => %Reference{"$ref": "#/components/schemas/post-filter-id"},
+                 "name" => %Reference{"$ref": "#/components/schemas/post-filter-name"},
+                 :and => %Schema{
                    type: :array,
                    items: %Reference{
                      "$ref": "#/components/schemas/post-filter"
                    },
                    uniqueItems: true
                  },
-                 or: %Schema{
+                 :or => %Schema{
                    type: :array,
                    items: %Reference{
                      "$ref": "#/components/schemas/post-filter"
                    },
                    uniqueItems: true
                  },
-                 name_twice: %Reference{
+                 "name_twice" => %Reference{
                    "$ref": "#/components/schemas/post-filter-name_twice"
                  },
-                 not: %Reference{"$ref": "#/components/schemas/post-filter"}
+                 :not => %Reference{"$ref": "#/components/schemas/post-filter"}
                },
                additionalProperties: false,
                example: ""