diff --git a/.travis.yml b/.travis.yml
index 7d916e1..503a8b7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ git:
 sudo: false
 cache:
   directories:
+  - node_modules
   - build-babel/node_modules
   - build-babel/jspm_packages
 language: node_js
@@ -15,4 +16,5 @@ matrix:
     - node_js: '5'
     - node_js: '6'
 before_script:
+  - "npm i jspm@beta --prefix build-babel" # Force install in build-babel/node_modules
   - "npm run build"
diff --git a/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.8.0/lib/util.js b/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.9.0/lib/util.js
similarity index 90%
rename from build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.8.0/lib/util.js
rename to build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.9.0/lib/util.js
index 9df81ca..9df0923 100644
--- a/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.8.0/lib/util.js
+++ b/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.9.0/lib/util.js
@@ -13,7 +13,7 @@ var t = _interopRequireWildcard(_babelTypes);
 function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }
 
 function runtimeProperty(name, regeneratorIdentifier) {
-  return t.memberExpression(regeneratorIdentifer || t.identifier("regeneratorRuntime"), t.identifier(name), false);
+  return t.memberExpression(regeneratorIdentifier || t.identifier("regeneratorRuntime"), t.identifier(name), false);
 } /**
    * Copyright (c) 2014, Facebook, Inc.
    * All rights reserved.
@@ -26,4 +26,4 @@ function runtimeProperty(name, regeneratorIdentifier) {
 
 function isReference(path) {
   return path.isReferenced() || path.parentPath.isAssignmentExpression({ left: path.node });
-}
\ No newline at end of file
+}
diff --git a/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.8.0/lib/visit.js b/build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.9.0/lib/visit.js
similarity index 100%
rename from build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.8.0/lib/visit.js
rename to build-babel/jspm_packages_override/npm/babel-plugin-transform-regenerator@6.9.0/lib/visit.js
diff --git a/build.sh b/build.sh
index 3377957..1e4ad8b 100755
--- a/build.sh
+++ b/build.sh
@@ -1,24 +1,49 @@
 #!/bin/bash -xv
 
 NODE_CWD=./node_modules/.bin
-
 JSPM_CMD=${NODE_CWD}/jspm
 
+BABEL_PLUGIN_TRANSFORM_REGENERATOR_VERSION=^6.9.0
+BUILD_DIR=build-babel
 JSPM_VERSION=beta
-REGENERATOR_VERSION=^0.9.5 
+REGENERATOR_VERSION=^0.9.5
+
+#
+
+function getLatestVersionFromRange
+{
+  local LATEST_VERSIONS=$(npm v $1 version)
+  local LATEST_VERSION
+  if [ $(echo $LATEST_VERSIONS | wc -l) = "1" ];then
+    LATEST_VERSION=$LATEST_VERSIONS
+  else
+    LATEST_VERSION=$(echo $LATEST_VERSIONS | tail -n 1 | awk '{print $2}' | tr -d "'")
+  fi
+
+  echo $LATEST_VERSION
+}
+
+function verifyLatestVersionOverrides
+{
+  local OVERRIDDEN_PACKAGE_DIR="$BUILD_DIR/jspm_packages_override/$1"
+  if [ ! -d "$OVERRIDDEN_PACKAGE_DIR" ];then
+    echo "Expect $OVERRIDDEN_PACKAGE_DIR to be found" 1>&2
+    exit 1
+  fi
+}
+
+#
+
+LATEST_REGENERATOR_VERSION=$(getLatestVersionFromRange regenerator-runtime@$REGENERATOR_VERSION)
+LATEST_BABEL_PLUGIN_TRANSFORM_REGENERATOR_VERSION=$(getLatestVersionFromRange babel-plugin-transform-regenerator@$BABEL_PLUGIN_TRANSFORM_REGENERATOR_VERSION)
 
 #
 
-LATEST_REGENERATOR_VERSIONS=$(npm v regenerator-runtime@$REGENERATOR_VERSION version)
-if [ $(echo $LATEST_REGENERATOR_VERSIONS | wc -l) = "1" ];then
-	REGENERATOR_VERSION=$LATEST_REGENERATOR_VERSIONS
-else
-	REGENERATOR_VERSION=$(echo $LATEST_REGENERATOR_VERSIONS | tail -n 1 | awk '{print $2}' | tr -d "'")
-fi
+verifyLatestVersionOverrides "npm/babel-plugin-transform-regenerator@$LATEST_BABEL_PLUGIN_TRANSFORM_REGENERATOR_VERSION"
 
 #
 
-cd build-babel
+cd $BUILD_DIR
 rm -rf jspm_packages node_modules
 
 npm install jspm@${JSPM_VERSION} --cache-min=Infinity
@@ -31,7 +56,7 @@ ${JSPM_CMD} run systemjs-build-babel-helpers.js > ../babel-helpers.js
 ${JSPM_CMD} run systemjs-build-modular-babel-helpers.js
 (
   echo "export default (function(module) {" ;
-  cat jspm_packages/npm/regenerator-runtime@${REGENERATOR_VERSION}/runtime.js
+  cat jspm_packages/npm/regenerator-runtime@$LATEST_REGENERATOR_VERSION/runtime.js
   echo "return module.exports; })({exports:{}});"
 ) > ../regenerator-runtime.js
 cd ..