diff --git a/.travis.yml b/.travis.yml
index 65b4303..ff951c3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -84,19 +84,6 @@ osx_xcode: &osx_xcode
   install:
     - python3 -m pip install conan --upgrade --user
 
-osx_xcode9: &osx_xcode9
-  <<: *osx_xcode
-  osx_image: xcode9
-  addons:
-    homebrew:
-      packages: [ python3, trang ]
-      # Homebrew must be updated before packages can be installed on outdated
-      # macOS images. The update process unfortunately takes a VERY long time
-      # and can even cause Travis to terminate the build. Travis caching is
-      # used to ensure Homebrew is kept up-to-date and build times are kept to
-      # a minimum.
-      update: true
-
 windows_vs2017: &windows_vs2017
   os: windows
   # Conan will automatically determine the best compiler for a given platform
@@ -159,9 +146,6 @@ jobs:
       env: [ ARCH=x86_64, ASAN=address, BUILD_TYPE=Debug, SSL=YES, SECURITY=NO, LIFESPAN=YES, DEADLINE=YES, GENERATOR="Unix Makefiles" ]
     - <<: *linux_clang
       env: [ ARCH=x86_64, ASAN=none, BUILD_TYPE=Release, SSL=YES, SECURITY=YES, LIFESPAN=YES, DEADLINE=YES, GENERATOR="Unix Makefiles" ]
-    - <<: *osx_xcode9
-      env: [ ARCH=x86_64, ASAN=none, BUILD_TYPE=Release, SSL=NO, SECURITY=YES, LIFESPAN=YES, DEADLINE=YES, GENERATOR="Unix Makefiles" ]
-      if: type = cron
     - <<: *osx_xcode
       env: [ ARCH=x86_64, ASAN=none, BUILD_TYPE=Release, SSL=NO, SECURITY=YES, LIFESPAN=YES, DEADLINE=YES, GENERATOR="Unix Makefiles", MACOSX_DEPLOYMENT_TARGET=10.12 ]
     - <<: *osx_xcode