diff --git a/.travis.yml b/.travis.yml
index 66043c7..bad3e69 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,6 @@
 language: cpp
 
+
 dist: trusty
 sudo: false
 
@@ -11,8 +12,24 @@ matrix:
           sources:
              - ubuntu-toolchain-r-test
           packages:
-             - g++-5
-      env: COMPILER=g++-5 CXXSTD=11
+             - g++-6
+      env: COMPILER=g++-6 CXXSTD=11
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-7
+      env: COMPILER=g++-7 CXXSTD=11
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-8
+      env: COMPILER=g++-8 CXXSTD=11
     - compiler: gcc
       addons:
         apt:
@@ -80,14 +97,61 @@ matrix:
             - clang++-3.9
             - libc++-dev
       env: COMPILER=clang++-3.9 CXXSTD=11
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-4.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-4.0
+             - libc++-dev
+      env: COMPILER=clang++-4.0 CXXSTD=11
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-5.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-5.0
+             - libc++-dev
+      env: COMPILER=clang++-5.0 CXXSTD=11
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-6.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-6.0
+             - libc++-dev
+      env: COMPILER=clang++-6.0 CXXSTD=11
+
     - compiler: gcc
       addons:
         apt:
           sources:
              - ubuntu-toolchain-r-test
           packages:
-             - g++-5
-      env: COMPILER=g++-5 CXXSTD=14
+             - g++-6
+      env: COMPILER=g++-6 CXXSTD=14
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-7
+      env: COMPILER=g++-7 CXXSTD=14
+    - compiler: gcc
+      addons:
+        apt:
+          sources:
+             - ubuntu-toolchain-r-test
+          packages:
+             - g++-8
+      env: COMPILER=g++-8 CXXSTD=14
     - compiler: clang
       addons:
         apt:
@@ -139,7 +203,36 @@ matrix:
             - clang++-3.9
             - libc++-dev
       env: COMPILER=clang++-3.9 CXXSTD=14
-
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-4.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-4.0
+             - libc++-dev
+      env: COMPILER=clang++-4.0 CXXSTD=14
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-5.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-5.0
+             - libc++-dev
+      env: COMPILER=clang++-5.0 CXXSTD=14
+    - compiler: clang
+      addons:
+        apt:
+          sources:
+             - llvm-toolchain-trusty-6.0
+             - ubuntu-toolchain-r-test
+          packages:
+             - clang++-6.0
+             - libc++-dev
+      env: COMPILER=clang++-6.0 CXXSTD=14
 
 install:
     - if [ "$CXX" = "clang++" ]; then export CXX="$COMPILER -stdlib=libc++"; fi
diff --git a/README.md b/README.md
index f68fcef..8b7d87d 100644
--- a/README.md
+++ b/README.md
@@ -90,21 +90,26 @@ o = j;
 
 Tested on:
 
-- Linux CI
+
+- Linux
+  * clang 6.0.1
+  * clang 5.0.2
+  * clang 4.0.1
   * clang 3.9
   * clang 3.8
   * clang 3.7
   * clang 3.6
   * clang 3.5
-  * g++ 5.0
+  * g++ 8.0.1
+  * g++ 7.3
+  * g++ 6.4
   * g++ 4.9
   * g++ 4.8
-- Windows CI
+- Windows
   * MSVC 2015
   * MSVC 2017
-- Linux manual
-  * g++ 7.2
-  * g++ 5.4
+
+Unfortunately GCC5.5 has a compiler bug which I have not worked around yet. All other GCC5 versions should work.
 
 ### Dependencies
 
diff --git a/tests/extensions.cpp b/tests/extensions.cpp
index 1524612..9eb024a 100644
--- a/tests/extensions.cpp
+++ b/tests/extensions.cpp
@@ -237,9 +237,14 @@ TEST_CASE("Monadic operations", "[monadic]") {
     REQUIRE(!o18r);
 
     const tl::optional<int> o19 = tl::nullopt;
-    auto o19r =
-        std::move(o19).and_then([](int i) { return tl::make_optional(42); });
+    auto o19r = std::move(o19).and_then([](int i) { return tl::make_optional(42); });
     REQUIRE(!o19r);
+
+    int i = 3;
+    tl::optional<int&> o20{i};
+    std::move(o20).and_then([](int& r){return tl::optional<int&>{++r};});
+    REQUIRE(o20);
+    REQUIRE(i == 4);
   }
 
   SECTION("constexpr and_then") {
diff --git a/tl/optional.hpp b/tl/optional.hpp
index da5bd3f..64e1324 100644
--- a/tl/optional.hpp
+++ b/tl/optional.hpp
@@ -138,9 +138,9 @@ template <class F, class, class... Us> struct invoke_result_impl;
 
 template <class F, class... Us>
 struct invoke_result_impl<
-    F, decltype(invoke(std::declval<F>(), std::declval<Us>()...), void()),
+    F, decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...), void()),
     Us...> {
-  using type = decltype(invoke(std::declval<F>(), std::declval<Us>()...));
+  using type = decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...));
 };
 
 template <class F, class... Us>
@@ -1707,11 +1707,11 @@ public:
   /// \group and_then
   /// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
   template <class F> TL_OPTIONAL_11_CONSTEXPR auto and_then(F &&f) && {
-    using result = detail::invoke_result_t<F, T &&>;
+    using result = detail::invoke_result_t<F, T &>;
     static_assert(detail::is_optional<result>::value,
                   "F must return an optional");
 
-    return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this))
+    return has_value() ? detail::invoke(std::forward<F>(f), **this)
                        : result(nullopt);
   }
 
@@ -1730,11 +1730,11 @@ public:
   /// \group and_then
   /// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
   template <class F> constexpr auto and_then(F &&f) const && {
-    using result = detail::invoke_result_t<F, const T &&>;
+    using result = detail::invoke_result_t<F, const T &>;
     static_assert(detail::is_optional<result>::value,
                   "F must return an optional");
 
-    return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this))
+    return has_value() ? detail::invoke(std::forward<F>(f), **this)
                        : result(nullopt);
   }
 #endif
@@ -1762,12 +1762,12 @@ public:
   /// \group and_then
   /// \synopsis template <class F>\nconstexpr auto and_then(F &&f) &&;
   template <class F>
-  TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T &&> and_then(F &&f) && {
-    using result = detail::invoke_result_t<F, T &&>;
+  TL_OPTIONAL_11_CONSTEXPR detail::invoke_result_t<F, T &> and_then(F &&f) && {
+    using result = detail::invoke_result_t<F, T &>;
     static_assert(detail::is_optional<result>::value,
                   "F must return an optional");
 
-    return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this))
+    return has_value() ? detail::invoke(std::forward<F>(f), **this)
                        : result(nullopt);
   }
 
@@ -1787,12 +1787,12 @@ public:
   /// \group and_then
   /// \synopsis template <class F>\nconstexpr auto and_then(F &&f) const &&;
   template <class F>
-  constexpr detail::invoke_result_t<F, const T &&> and_then(F &&f) const && {
-    using result = detail::invoke_result_t<F, const T &&>;
+  constexpr detail::invoke_result_t<F, const T &> and_then(F &&f) const && {
+    using result = detail::invoke_result_t<F, const T &>;
     static_assert(detail::is_optional<result>::value,
                   "F must return an optional");
 
-    return has_value() ? detail::invoke(std::forward<F>(f), std::move(**this))
+    return has_value() ? detail::invoke(std::forward<F>(f), **this)
                        : result(nullopt);
   }
 #endif