--- a/mozilla-tests/config.py
+++ b/mozilla-tests/config.py
@@ -2007,33 +2007,34 @@ for platform in PLATFORMS.keys():
         if slave_platform not in BRANCHES['cedar']['platforms'][platform]:
             continue
         BRANCHES['cedar']['platforms'][platform][slave_platform]['opt_unittest_suites'] += MOCHITEST_JP[:]
         BRANCHES['cedar']['platforms'][platform][slave_platform]['debug_unittest_suites'] += MOCHITEST_JP[:]
 
 # Enable e10s Linux mochitests on trunk branches
 # Enable e10s browser-chrome mochitests on trunk branches, opt builds only for all platforms (not ready for Xp).
 # Enable e10s devtools tests for Linux opt on trunk branches
+# Enable e10s reftests/crashtests for Linux opt on trunk branches
 # Fix this to a certain gecko version once e10s starts riding the trains
 mc_gecko_version = BRANCHES['mozilla-central']['gecko_version']
 for name, branch in items_at_least(BRANCHES, 'gecko_version', mc_gecko_version):
     if name == "holly": # On Holly we use normal mochitest as e10s ones
         continue
     for platform in PLATFORMS.keys():
         if platform not in branch['platforms']:
             continue
         for slave_platform in PLATFORMS[platform]['slave_platforms']:
             if platform in branch['platforms'] and slave_platform in branch['platforms'][platform] and \
                     not slave_platform == 'xp-ix':
                 branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += MOCHITEST_BC_3_E10S[:]
             if platform in ('linux', 'linux64', 'linux64-asan'):
                 branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += MOCHITEST_E10S[:]
             if platform in ('linux', 'linux64'):
                 branch['platforms'][platform][slave_platform]['debug_unittest_suites'] += MOCHITEST_E10S[:]
-                branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += MOCHITEST_DT_E10S[:]
+                branch['platforms'][platform][slave_platform]['opt_unittest_suites'] += MOCHITEST_DT_E10S[:] + REFTEST_E10S[:]
 
 # Bug 1080134: we want to disable all 32-bit testing on win8 for gecko 36 and
 # higher, and enable 64-bit tests on win8 instead.
 # Disable 64-bit win8 testing on gecko 35 and lower
 for name, branch in items_before(BRANCHES, 'gecko_version', 36):
     if 'win64' in branch['platforms']:
         del branch['platforms']['win64']
 for name, branch in items_at_least(BRANCHES, 'gecko_version', 36):