diff --git a/Koha/REST/Plugin/Exceptions.pm b/Koha/REST/Plugin/Exceptions.pm
index e9be043aa2..b069711596 100644
--- a/Koha/REST/Plugin/Exceptions.pm
+++ b/Koha/REST/Plugin/Exceptions.pm
@@ -76,11 +76,11 @@ sub register {
                 status  => 500,
                 openapi => {
                     error =>
-                      "Something went wrong, check Koha logs for details."
+                      "Something went wrong, check Koha logs for details.",
+                    error_code => 'internal_server_error',
                 }
             );
-          }
-
+        }
     );
 }
 
diff --git a/api/v1/swagger/definitions/error.yaml b/api/v1/swagger/definitions/error.yaml
index 8576374a8b..8f52da4c13 100644
--- a/api/v1/swagger/definitions/error.yaml
+++ b/api/v1/swagger/definitions/error.yaml
@@ -4,4 +4,7 @@ properties:
   error:
     description: Error message
     type: string
+  error_code:
+    description: Error code
+    type: string
 additionalProperties: true