diff --git a/.swift-version b/.swift-version
index fae6e3d..f2c6cb6 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-4.2.1
+4.2.3
diff --git a/.travis.yml b/.travis.yml
index a467169..3e167f0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,34 +12,33 @@ branches:
 matrix:
   include:
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
-      env: SWIFT_SNAPSHOT=4.0.3
-    - os: linux
-      dist: trusty
-      sudo: required
-      env: SWIFT_SNAPSHOT=4.1.3
+      services: docker
+      env: DOCKER_IMAGE=swift:4.0.3 SWIFT_SNAPSHOT=4.0.3
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
+      services: docker
+      env: DOCKER_IMAGE=swift:4.1.3 SWIFT_SNAPSHOT=4.1.3
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
       services: docker
-      env: DOCKER_IMAGE=ubuntu:16.04
+      env: DOCKER_IMAGE=swift:4.2.3
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
       services: docker
-      env: DOCKER_IMAGE=ubuntu:16.04 SWIFT_SNAPSHOT=$SWIFT_DEVELOPMENT_SNAPSHOT CUSTOM_TEST_SCRIPT=.kitura-test.sh DOCKER_ENVIRONMENT=CUSTOM_TEST_SCRIPT
+      env: DOCKER_IMAGE=swift:4.2.3 SWIFT_SNAPSHOT=$SWIFT_DEVELOPMENT_SNAPSHOT CUSTOM_TEST_SCRIPT=.kitura-test.sh DOCKER_ENVIRONMENT=CUSTOM_TEST_SCRIPT
       # Test GCD_ASYNCH codepath on Linux
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
       services: docker
-      env: DOCKER_IMAGE=ubuntu:16.04 SWIFT_SNAPSHOT=$SWIFT_DEVELOPMENT_SNAPSHOT CUSTOM_TEST_SCRIPT=testWithGCD.sh DOCKER_ENVIRONMENT=CUSTOM_TEST_SCRIPT
+      env: DOCKER_IMAGE=swift:4.2.3 SWIFT_SNAPSHOT=$SWIFT_DEVELOPMENT_SNAPSHOT CUSTOM_TEST_SCRIPT=testWithGCD.sh DOCKER_ENVIRONMENT=CUSTOM_TEST_SCRIPT
     - os: linux
-      dist: trusty
+      dist: xenial
       sudo: required
       services: docker
       env: DOCKER_IMAGE=ubuntu:18.04