diff --git a/internal/company/form.go b/internal/company/form.go
index 181b1dd..80a8942 100644
--- a/internal/company/form.go
+++ b/internal/company/form.go
@@ -76,7 +76,7 @@ type SearchForm struct {
 	FoundedYearMax   *int     `query:"founded_year_max" valid:"optional,range(1800|2100)"`
 	Limit            *int     `query:"limit" valid:"optional,range(1|100)"`
 	Offset           *int     `query:"offset" valid:"optional,range(0|1000000)"`
-	SortBy           *string  `query:"sort_by" valid:"optional,in(name|type|industry|created_at|updated_at|status|employee_count|annual_revenue|email|phone|country|state|language|currency)"`
+	SortBy           *string  `query:"sort_by" valid:"optional,in(name|type|industry|created_at|updated_at|status|employee_count|annual_revenue|email|phone|country|state|address.country|address.state|language|currency)"`
 	SortOrder        *string  `query:"sort_order" valid:"optional,in(asc|desc)"`
 }
 
diff --git a/pkg/mongo/cursor_test.go b/pkg/mongo/cursor_test.go
index fad37c4..b776b6d 100644
--- a/pkg/mongo/cursor_test.go
+++ b/pkg/mongo/cursor_test.go
@@ -53,3 +53,29 @@ func TestHashFilterStable(t *testing.T) {
 		t.Fatalf("expected stable non-empty hash, got %q and %q", a, b)
 	}
 }
+
+func TestDocumentSortValueNestedField(t *testing.T) {
+	doc := bson.M{
+		"_id": bson.NewObjectID(),
+		"address": bson.M{
+			"country": "US",
+			"state":   "NY",
+		},
+	}
+
+	country, err := documentSortValue(doc, "address.country")
+	if err != nil {
+		t.Fatalf("address.country: %v", err)
+	}
+	if country != "US" {
+		t.Fatalf("expected US, got %v", country)
+	}
+
+	state, err := documentSortValue(doc, "address.state")
+	if err != nil {
+		t.Fatalf("address.state: %v", err)
+	}
+	if state != "NY" {
+		t.Fatalf("expected NY, got %v", state)
+	}
+}