diff --git a/.travis.yml b/.travis.yml
index c83a27f..3b8ac0d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,7 +6,7 @@ language: cpp
 
 sudo: false
 
-dist: trusty
+dist: xenial
 
 branches:
   only:
@@ -108,7 +108,6 @@ matrix:
             - libstdc++-4.9-dev
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-precise-3.5
 
     - os: linux
       compiler: clang++-3.6
@@ -119,7 +118,6 @@ matrix:
             - clang-3.6
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-precise-3.6
 
     - os: linux
       compiler: clang++-3.7
@@ -130,7 +128,6 @@ matrix:
             - clang-3.7
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-precise-3.7
 
     - os: linux
       compiler: clang++-3.8
@@ -141,7 +138,6 @@ matrix:
             - clang-3.8
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-precise-3.8
 
     - os: linux
       compiler: clang++-3.9
@@ -152,7 +148,6 @@ matrix:
             - clang-3.9
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-precise-3.9
 
     - os: linux
       compiler: clang++-4.0
@@ -163,7 +158,6 @@ matrix:
             - clang-4.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-4.0
 
     - os: linux
       compiler: clang++-5.0
@@ -174,7 +168,6 @@ matrix:
             - clang-5.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
 
     - os: linux
       compiler: clang++-6.0
@@ -185,7 +178,6 @@ matrix:
             - clang-6.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
 
     - os: linux
       compiler: clang++-7
@@ -196,7 +188,7 @@ matrix:
             - clang-7
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-7
+            - llvm-toolchain-xenial-7
 
     - os: linux
       compiler: clang++-8
@@ -207,18 +199,31 @@ matrix:
             - clang-8
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-8
+            - llvm-toolchain-xenial-8
 
     - os: linux
-      compiler: clang++-6.0
+      dist: xenial
+      compiler: clang++-9
+      env: TOOLSET=clang COMPILER=clang++-9 CXXSTD=11,14,17,2a
+      addons:
+        apt:
+          packages:
+            - clang-9
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main'
+              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
+
+    - os: linux
+      compiler: clang++-8
       env: UBSAN=1 TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1
       addons:
         apt:
           packages:
-            - clang-6.0
+            - clang-8
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
+            - llvm-toolchain-xenial-6.0
 
     - os: linux
       compiler: clang++-libc++