diff --git a/.travis.yml b/.travis.yml
index 0ecc47e..514cf21 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,8 +6,6 @@ language: cpp
 
 sudo: false
 
-python: "2.7"
-
 branches:
   only:
     - master
@@ -109,7 +107,7 @@ matrix:
 
     - os: linux
       compiler: g++-8
-      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17
+      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17,2a
       addons:
         apt:
           packages:
@@ -320,6 +318,17 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-trusty-6.0
 
+    - os: linux
+      compiler: clang++-7
+      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-7
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-7
+
     - os: linux
       compiler: clang++-6.0
       env: UBSAN=1 TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,1z UBSAN_OPTIONS=print_stacktrace=1
@@ -358,7 +367,9 @@ install:
   - git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
   - cd boost-root
   - git submodule update --init tools/build
+  - git submodule update --init tools/boost_install
   - git submodule update --init libs/config
+  - git submodule update --init libs/headers
   - git submodule update --init tools/boostdep
   - cp -r $TRAVIS_BUILD_DIR/* libs/system
   - python tools/boostdep/depinst/depinst.py system
diff --git a/appveyor.yml b/appveyor.yml
index 2e8c6dd..4bda3fa 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -47,9 +47,11 @@ install:
   - git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
   - cd boost-root
   - git submodule update --init tools/build
+  - git submodule update --init tools/boost_install
   - git submodule update --init libs/config
+  - git submodule update --init libs/headers
   - git submodule update --init tools/boostdep
-  - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\system
+  - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\system\
   - python tools/boostdep/depinst/depinst.py system
   - cmd /c bootstrap
   - b2 -d0 headers