diff --git a/.travis.yml b/.travis.yml
index e38cca90fecf..6c9e18100db0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,6 +23,7 @@ env:
   - TEST_COMMAND='mx/mx canonicalizeprojects'
   - TEST_COMMAND='mx/mx checkstyle'
   - TEST_COMMAND='sh .travis.sigtest.sh'
-  
-
-
+  - TEST_COMMAND='mx/mx testdownstream'
+matrix:
+  allow_failures:
+    - env: TEST_COMMAND='mx/mx testdownstream'
diff --git a/mx.truffle/mx_truffle.py b/mx.truffle/mx_truffle.py
index 3c66687041f6..89c9b3edffa4 100644
--- a/mx.truffle/mx_truffle.py
+++ b/mx.truffle/mx_truffle.py
@@ -26,6 +26,9 @@
 #
 # ----------------------------------------------------------------------------------------------------
 
+import os
+import subprocess
+
 import mx
 
 from mx_unittest import unittest
@@ -54,6 +57,26 @@ def sldebug(args):
     vmArgs, slArgs = mx.extract_VM_args(args, useDoubleDash=True)
     mx.run_java(vmArgs + ['-cp', mx.classpath("com.oracle.truffle.sl.tools"), "com.oracle.truffle.sl.tools.debug.SLREPL"] + slArgs)
 
+def testdownstream(args):
+    """test downstream users of the Truffle API"""
+    jruby_dir = 'jruby'
+    jruby_repo = 'https://github.com/jruby/jruby.git'
+    jruby_branch = 'truffle-head'
+    git = mx.GitConfig()
+    if os.path.exists('jruby'):
+        git.run(['git', 'reset', 'HEAD', '--hard'], nonZeroIsFatal=True, cwd=jruby_dir)
+        git.pull('jruby')
+    else:
+        git.clone(jruby_repo, jruby_dir)
+        git.run(['git', 'checkout', jruby_branch], nonZeroIsFatal=True, cwd=jruby_dir)
+    dev_version = _suite.release_version(snapshotSuffix='SNAPSHOT')
+    subprocess.check_call(['tool/truffle/set_truffle_version.sh', dev_version], cwd=jruby_dir)
+    mx.build([])
+    mx.maven_install([])
+    subprocess.check_call(['./mvnw', 'clean'], cwd=jruby_dir)
+    subprocess.check_call(['./mvnw'], cwd=jruby_dir)
+    subprocess.check_call(['bin/jruby', 'tool/jt.rb', 'test', 'fast'], cwd=jruby_dir)
+
 def _truffle_gate_runner(args, tasks):
     with Task('Truffle Javadoc', tasks) as t:
         if t: mx.javadoc(['--unified'])
@@ -68,4 +91,5 @@ def _truffle_gate_runner(args, tasks):
     'javadoc' : [javadoc, '[SL args|@VM options]'],
     'sl' : [sl, '[SL args|@VM options]'],
     'sldebug' : [sldebug, '[SL args|@VM options]'],
+    'testdownstream' : [testdownstream, ''],
 })