diff --git a/src/exchange/taler-exchange-httpd_extensions.c b/src/exchange/taler-exchange-httpd_extensions.c
index 21d03209d..4c826e8bc 100644
--- a/src/exchange/taler-exchange-httpd_extensions.c
+++ b/src/exchange/taler-exchange-httpd_extensions.c
@@ -184,7 +184,7 @@ extension_update_event_cb (void *cls,
     qs = TEH_plugin->get_extension_config (TEH_plugin->cls,
                                            extension->name,
                                            &config_str,
-					   &config_sig);
+                                           &config_sig);
 
     if (qs < 0)
     {