diff --git a/.travis.yml b/.travis.yml
index d88f2b8..2220629 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,11 @@ deploy:
     tags: true
     repo: baztian/jaydebeapi
 
+cache:
+  directories:
+  - $TRAVIS_BUILD_DIR/.tox/shared/.m2
+  - $HOME/jython
+
 python:
   - '2.6'
   - '2.7'
diff --git a/ci/before_install_jython.sh b/ci/before_install_jython.sh
index c9c5826..8bdb549 100755
--- a/ci/before_install_jython.sh
+++ b/ci/before_install_jython.sh
@@ -1,7 +1,10 @@
 #!/bin/sh
 set -e
 
-JYTHON_JAR=$(${TRAVIS_BUILD_DIR}/ci/mvnget.sh "$JYTHON")
-java -jar ${JYTHON_JAR} -s -d $HOME/jython
+INST_DIR=$HOME/jython/jython-${JYTHON##*:}
+if [ ! -d "$INST_DIR" ]; then
+    JYTHON_JAR=$(${TRAVIS_BUILD_DIR}/ci/mvnget.sh "$JYTHON")
+    java -jar ${JYTHON_JAR} -s -d "$INST_DIR"
+fi
 mkdir -p $HOME/bin
-ln -s $HOME/jython/bin/jython $HOME/bin/
+ln -s "$INST_DIR"/bin/jython $HOME/bin/
diff --git a/tox.ini b/tox.ini
index 1cf242f..3a237b3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,6 @@ python =
 # usedevelop required to enable coveralls source code view.
 usedevelop=True
 whitelist_externals = mvn
-passenv = TRAVIS TRAVIS_JOB_ID TRAVIS_BRANCH
 setenv =
   CLASSPATH = {envdir}/javalib/*
   driver-mock: TESTNAME=test_mock