diff --git a/.travis-before_install.sh b/.travis-before_install.sh
index b587f6da6..7bd53f387 100755
--- a/.travis-before_install.sh
+++ b/.travis-before_install.sh
@@ -38,7 +38,7 @@ sudo apt-get install -y -qq
 
 if [ "$Compiler_version" != "" ] && [ "$Compiler_version" != "default" ]; then
     if [ "$Compiler_name" = "gcc" ]; then
-	sudo apt-get install -qq gcc-${Compiler_version} g++-${Compiler_version}
+	sudo apt-get --allow-unauthenticated install -qq --force-yes gcc-${Compiler_version} g++-${Compiler_version}
     elif [ "$Compiler_name" = "clang" ]; then
 	sudo apt-get --allow-unauthenticated install -qq --force-yes clang-${Compiler_version}
     fi
diff --git a/.travis.yml b/.travis.yml
index 621aed48f..33f423aef 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ matrix:
     - os: linux
       compiler: gcc
       env: Tr_Compiler_Version="6"
-      dist: trusty
+      dist: trusty # broken compiler on 12.04
       # https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test
     - os: linux
       compiler: gcc
@@ -20,15 +20,12 @@ matrix:
       compiler: clang
       env: Tr_Compiler_Version="3.8"
       # http://apt.llvm.org/
-    - os: linux
-      compiler: clang
-      env: Tr_Compiler_Version="3.7"
     #- os: linux
       #compiler: clang
-      #env: Tr_Compiler_Version="default" # broken compiler
+      #env: Tr_Compiler_Version="default" # broken compiler on 12.04
     - os: osx
-      osx_image: xcode7.3
-      env: Tr_Xcode_Version="8"
+      osx_image: xcode7
+      env: Tr_Xcode_Version="7"
       # https://docs.travis-ci.com/user/osx-ci-environment/#OS-X-Version
     - os: osx
       env: Tr_Xcode_Version="default"
@@ -37,12 +34,9 @@ matrix:
     - os: linux
       compiler: gcc
       env: Tr_Compiler_Version="6"
-    - os: linux
-      compiler: clang
-      env: Tr_Compiler_Version="3.8"
     - os: osx
-      osx_image: xcode8
-      env: Tr_Xcode_Version="8"
+      osx_image: xcode7
+      env: Tr_Xcode_Version="7"
 
 git:
   submodules: false