diff --git a/.travis.yml b/.travis.yml
index 9bd344af146237ffe8c293f5f5dd706f3321ff5b..3d54360291cbff67b901a9eb269c1a901f3fd1f5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@ notifications:
 matrix:
   include:
     - os: osx
-      osx_image: xcode11.3 #xcode10.2 # for c++17
+      osx_image: xcode10.2 # for c++17
       compiler: clang
       addons:
         homebrew:
diff --git a/lib/structs/user_interactive.cpp b/lib/structs/user_interactive.cpp
index 17df7770c751b47977b5183d8b66f487698121d8..0d178d01ce47beb6d5c797b5bb9d4bd02dd33030 100644
--- a/lib/structs/user_interactive.cpp
+++ b/lib/structs/user_interactive.cpp
@@ -118,7 +118,7 @@ to_json(nlohmann::json &obj, const Auth &auth)
                      [&obj](const auth::OAuth2 &) { obj["type"] = auth_types::oauth2; },
                      [&obj](const auth::Terms &) { obj["type"] = auth_types::terms; },
                      [&obj](const auth::Dummy &) { obj["type"] = auth_types::dummy; },
-                     [&obj](const auth::Fallback &) {},
+                     [](const auth::Fallback &) {},
                    },
                    auth.content);
 }