diff --git a/.travis.yml b/.travis.yml
index 37b2ce3..875ef59 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,6 +29,11 @@ env:
 
 matrix:
   fast_finish: true
+  include:
+    - php: "5.5"
+      env: UPGRADE=none INSTALL_PANOPOLY_DEMO_FROM_APPS=1
+    - php: "5.6"
+      env: UPGRADE=none INSTALL_PANOPOLY_DEMO_FROM_APPS=1
 
 install:
   # Make some variables available to the travis-ci.sh script.
diff --git a/scripts/travis-ci.sh b/scripts/travis-ci.sh
index a3b33a3..97c7280 100755
--- a/scripts/travis-ci.sh
+++ b/scripts/travis-ci.sh
@@ -100,8 +100,10 @@ system_install() {
   echo sendmail_path=`which true` >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
 
   # Enable APC
-  echo "extension=apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
-  echo "apc.shm_size=256M" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
+  if [[ $TRAVIS_PHP_VERSION < "5.5" ]]; then
+    echo "extension=apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
+    echo "apc.shm_size=256M" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
+  fi
 
   # Increase the MySQL connection timeout on the PHP end.
   echo "mysql.connect_timeout=3000" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini