diff --git a/src/json-rpc2.lisp b/src/json-rpc2.lisp
index b538ebc..e990dac 100644
--- a/src/json-rpc2.lisp
+++ b/src/json-rpc2.lisp
@@ -411,10 +411,14 @@
                           :error-object (make-response-error (or (code e)
                                                                  (response-error-code +error-invalid-request+))
                                                              (text e))))
-         (make-internal-error (e &optional (id nil))
+         (make-internal-error (e)
+           (make-response nil
+                          nil
+                          :error-object (make-internal-error-message (format nil "~a" e))))
+         (make-failed-function-error (e id)
            (make-response nil
                           id
-                          :error-object (make-internal-error-message (format nil "~a" e)))))
+                          :error-object (make-failed-function-call-error-message (format nil "~a" e)))))
   (handler-case
       (multiple-value-bind (method id params)
           (displace-single-request request)
@@ -430,7 +434,7 @@
             (make-rpc-error e))
           (error (e)
             (maybe-log-message (format nil "jsonrpc request failed: ~a" e))
-            (make-internal-error e id))))
+            (make-failed-function-error e id))))
     (json-rpc-error (e)
       (make-rpc-error e))
     (error (e)