diff --git a/lang/en/webservice.php b/lang/en/webservice.php
index 075ca231585..20127684198 100644
--- a/lang/en/webservice.php
+++ b/lang/en/webservice.php
@@ -24,7 +24,6 @@
  */
 
 $string['accessexception'] = 'Access control exception';
-$string['accessnotallowed'] = 'Access to web service not allowed';
 $string['actwebserviceshhdr'] = 'Active web service protocols';
 $string['accesstofunctionnotallowed'] = 'Access to the function {$a}() is not allowed. Please check if a service containing the function is enabled. In the service settings: if the service is restricted check that the user is listed. Still in the service settings check for IP restriction or if the service requires a capability.';
 $string['addaservice'] = 'Add service';
@@ -130,6 +129,7 @@ $string['potusers'] = 'Not authorised users';
 $string['potusersmatching'] = 'Not authorised users matching';
 $string['print'] = 'Print all';
 $string['protocol'] = 'Protocol';
+$string['protocolnotallowed'] = 'You are not allowed to use the {$a} protocol (missing capability: webservice/{$a}:use)';
 $string['removefunction'] = 'Remove';
 $string['removefunctionconfirm'] = 'Do you really want to remove function "{$a->function}" from service "{$a->service}"?';
 $string['requireauthentication'] = 'This method requires authentication with xxx permission.';
diff --git a/webservice/lib.php b/webservice/lib.php
index 84c0927caae..d5f5cda93d4 100644
--- a/webservice/lib.php
+++ b/webservice/lib.php
@@ -659,7 +659,7 @@ abstract class webservice_server implements webservice_server_interface {
         $this->userid = $user->id;
 
         if ($this->authmethod != WEBSERVICE_AUTHMETHOD_SESSION_TOKEN && !has_capability("webservice/$this->wsname:use", $this->restricted_context)) {
-            throw new webservice_access_exception(get_string('accessnotallowed', 'webservice'));
+            throw new webservice_access_exception(get_string('protocolnotallowed', 'webservice', $this->wsname));
         }
 
         external_api::set_context_restriction($this->restricted_context);