diff --git a/src/Datatrans.ts b/src/Datatrans.ts
index 2109faf..f484118 100644
--- a/src/Datatrans.ts
+++ b/src/Datatrans.ts
@@ -22,7 +22,7 @@ export interface GlobalDatatransApi {
  */
 export interface DatatransLightboxConfig {
   closed?: () => void;
-  error?: () => void;
+  error?: (error: { message: string; detail: string }) => void;
   form?: unknown;
   loaded?: () => void;
   opened?: () => void;
diff --git a/src/Lightbox.tsx b/src/Lightbox.tsx
index 744d728..ec2c9a0 100644
--- a/src/Lightbox.tsx
+++ b/src/Lightbox.tsx
@@ -12,7 +12,7 @@ export interface LightboxProps {
   onLoaded?: () => void
   onOpened?: () => void
   onCancelled?: () => void
-  onError?: () => void
+  onError?: (error: { message: string; detail: string }) => void
 }
 
 declare let window: Window & {