diff --git a/.travis.yml b/.travis.yml
index 6de4a9f8..422954e5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -93,9 +93,9 @@ script:
   # - pushd third-party/ispc && rm -rf ispc-* && ./get-ispc.sh; popd
 
   # use this to update versons of embree ospray rapidjson 
-  # - rm .galaxy/gxy_third_party_installed ; GXY_REBUILDING_CACHE=1
-  # - rm -rf third-party/embree third-party/ospray third-party/rapidjson
-  # - scripts/install-third-party.sh
+  - rm .galaxy/gxy_third_party_prep_done .galaxy/gxy_third_party_installed ; GXY_REBUILDING_CACHE=1
+  - rm -rf third-party/embree third-party/ospray third-party/rapidjson
+  - scripts/install-third-party.sh
 
 
   # use this to rebuild embree and ospray
@@ -109,7 +109,7 @@ script:
   # 1. build Galaxy interactive interface
   # 2. build Galaxy image writing interface
   # 3. run gold image tests
-  - scripts/travis-ci-build.sh
+  - if [ -z ${GXY_REBUILDING_CACHE} ]; then scripts/travis-ci-build.sh; fi
   - if [ -z ${GXY_REBUILDING_CACHE} ] && [ -f install/bin/gxywriter ] && [ "${TRAVIS_OS_NAME}" == "linux" ]; then tests/image-gold-tests.sh; fi
   - if [ -z ${GXY_REBUILDING_CACHE} ] && [ -d install/tests ]; then tests/unit-tests.sh; fi
   - echo $(date) > .galaxy/last_build