--- a/taskcluster/ci/desktop-test/test-sets.yml
+++ b/taskcluster/ci/desktop-test/test-sets.yml
@@ -84,13 +84,14 @@ windows-vm-tests:
 # these tests currently run on hardware, but may migrate above when validated
 # note: on win, mochitest-a11y and mochitest-chrome come under mochitest-other
 # windows-hw-tests:
 #    - mochitest-clipboard
 #    - mochitest-gpu
 #    - mochitest-other
 
 ccov-code-coverage-tests:
+    - mochitest
     - mochitest-browser-chrome
     - mochitest-devtools-chrome
 
 jsdcov-code-coverage-tests:
     - mochitest-browser-chrome
\ No newline at end of file

--- a/taskcluster/ci/desktop-test/tests.yml
+++ b/taskcluster/ci/desktop-test/tests.yml
@@ -173,34 +173,47 @@ marionette:
                     - marionette/prod_config.py
                     - remove_executables.py
 
 mochitest:
     description: "Mochitest plain run"
     suite: mochitest/plain-chunked
     treeherder-symbol: tc-M()
     loopback-video: true
+    run-on-projects:
+        by-test-platform:
+            linux64-ccov/opt: []
+            default: ['all']
     chunks:
         by-test-platform:
             win.*: 5
             default: 10
+    e10s:
+        by-test-platform:
+            linux64-ccov/opt: false
+            default: both
     max-run-time: 5400
     mozharness:
         script: desktop_unittest.py
         no-read-buildbot-config: true
         chunked: true
         config:
             by-test-platform:
                 win.*:
                     - unittests/win_taskcluster_unittest.py
                 default:
                     - unittests/linux_unittest.py
                     - remove_executables.py
         extra-options:
-            - --mochitest-suite=plain-chunked
+            by-test-platform:
+                linux64-ccov/opt:
+                    - --mochitest-suite=plain-chunked
+                    - --code-coverage
+                default:
+                    - --mochitest-suite=plain-chunked
     # Bug 1281241: migrating to m3.large instances
     instance-size: legacy
     allow-software-gl-layers: false
 
 mochitest-a11y:
     description: "Mochitest a11y run"
     suite: mochitest/a11y
     treeherder-symbol: tc-M(a11y)