diff --git a/.travis.yml b/.travis.yml
index c05a642..1827fda 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -35,6 +35,7 @@ matrix:
     - os: linux
       compiler: g++-4.4
       env: TOOLSET=gcc COMPILER=g++-4.4 CXXSTD=98,0x
+      dist: trusty
       addons:
         apt:
           packages:
@@ -45,6 +46,7 @@ matrix:
     - os: linux
       compiler: g++-4.6
       env: TOOLSET=gcc COMPILER=g++-4.6 CXXSTD=03,0x
+      dist: trusty
       addons:
         apt:
           packages:
@@ -54,6 +56,7 @@ matrix:
 
     - os: linux
       env: TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11
+      dist: trusty
       addons:
         apt:
           packages:
@@ -72,6 +75,7 @@ matrix:
 
     - os: linux
       env: TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11
+      dist: trusty
       addons:
         apt:
           packages:
@@ -155,53 +159,58 @@ matrix:
 
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03,11
+      dist: trusty
       addons:
         apt:
           packages:
             - clang-3.5
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-3.5
+            - llvm-toolchain-trusty-3.5
 
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03,11
+      dist: trusty
       addons:
         apt:
           packages:
             - clang-3.6
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-3.6
+            - llvm-toolchain-trusty-3.6
 
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03,11
+      dist: trusty
       addons:
         apt:
           packages:
             - clang-3.7
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-3.7
+            - llvm-toolchain-trusty-3.7
 
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03,11,14,1z
+      dist: trusty
       addons:
         apt:
           packages:
             - clang-3.8
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-3.8
+            - llvm-toolchain-trusty-3.8
 
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03,11,14,1z
+      dist: trusty
       addons:
         apt:
           packages:
             - clang-3.9
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-3.9
+            - llvm-toolchain-trusty-3.9
 
     - os: linux
       compiler: clang++-4.0
@@ -212,7 +221,7 @@ matrix:
             - clang-4.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-4.0
+            - llvm-toolchain-xenial-4.0
 
     - os: linux
       compiler: clang++-5.0
@@ -223,7 +232,7 @@ matrix:
             - clang-5.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
+            - llvm-toolchain-xenial-5.0
 
     - os: linux
       compiler: clang++-6.0
@@ -234,7 +243,7 @@ matrix:
             - clang-6.0
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
+            - llvm-toolchain-xenial-6.0
 
     - os: linux
       compiler: clang++-7
@@ -245,7 +254,7 @@ matrix:
             - clang-7
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-7
+            - llvm-toolchain-xenial-7
 
     - os: osx
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z