diff --git a/internal/http/response/html/html.go b/internal/http/response/html/html.go
index fe21b0a2..04fbaf28 100644
--- a/internal/http/response/html/html.go
+++ b/internal/http/response/html/html.go
@@ -13,7 +13,7 @@ import (
 )
 
 // OK creates a new HTML response with a 200 status code.
-func OK(w http.ResponseWriter, r *http.Request, body interface{}) {
+func OK[T []byte | string](w http.ResponseWriter, r *http.Request, body T) {
 	builder := response.New(w, r)
 	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
 	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
diff --git a/internal/http/response/xml/xml.go b/internal/http/response/xml/xml.go
index 4329197b..bc298e29 100644
--- a/internal/http/response/xml/xml.go
+++ b/internal/http/response/xml/xml.go
@@ -10,7 +10,7 @@ import (
 )
 
 // OK writes a standard XML response with a status 200 OK.
-func OK(w http.ResponseWriter, r *http.Request, body interface{}) {
+func OK[T []byte | string](w http.ResponseWriter, r *http.Request, body T) {
 	builder := response.New(w, r)
 	builder.WithHeader("Content-Type", "text/xml; charset=utf-8")
 	builder.WithBody(body)
@@ -18,7 +18,7 @@ func OK(w http.ResponseWriter, r *http.Request, body interface{}) {
 }
 
 // Attachment forces the XML document to be downloaded by the web browser.
-func Attachment(w http.ResponseWriter, r *http.Request, filename string, body interface{}) {
+func Attachment[T []byte | string](w http.ResponseWriter, r *http.Request, filename string, body T) {
 	builder := response.New(w, r)
 	builder.WithHeader("Content-Type", "text/xml; charset=utf-8")
 	builder.WithAttachment(filename)