diff --git a/devtools/server/tests/unit/xpcshell.ini b/devtools/server/tests/unit/xpcshell.ini
index 49b8e4c67df9..3f8efab1b068 100644
--- a/devtools/server/tests/unit/xpcshell.ini
+++ b/devtools/server/tests/unit/xpcshell.ini
@@ -91,6 +91,7 @@ support-files =
 [test_promises_actor_attach.js]
 [test_promises_actor_exist.js]
 [test_promises_actor_list_promises.js]
+skip-if = coverage # bug 1336670
 [test_promises_actor_onnewpromise.js]
 [test_promises_actor_onpromisesettled.js]
 [test_promises_client_getdependentpromises.js]
diff --git a/dom/indexedDB/test/unit/xpcshell-parent-process.ini b/dom/indexedDB/test/unit/xpcshell-parent-process.ini
index f966837c617a..95d6f89d36f1 100644
--- a/dom/indexedDB/test/unit/xpcshell-parent-process.ini
+++ b/dom/indexedDB/test/unit/xpcshell-parent-process.ini
@@ -65,5 +65,8 @@ skip-if = true
 skip-if = os == "android" && processor == "x86"
 [test_view_put_get_values.js]
 [test_wasm_getAll.js]
+skip-if = coverage # bug 1336727
 [test_wasm_put_get_values.js]
+skip-if = coverage # bug 1336727
 [test_wasm_recompile.js]
+skip-if = coverage # bug 1336727
diff --git a/security/manager/ssl/tests/unit/xpcshell-smartcards.ini b/security/manager/ssl/tests/unit/xpcshell-smartcards.ini
index df099b7469d9..66f4d842642f 100644
--- a/security/manager/ssl/tests/unit/xpcshell-smartcards.ini
+++ b/security/manager/ssl/tests/unit/xpcshell-smartcards.ini
@@ -9,6 +9,7 @@ support-files =
 [test_pkcs11_module.js]
 [test_pkcs11_no_events_after_removal.js]
 [test_pkcs11_safe_mode.js]
+skip-if = coverage # bug 1336728
 [test_pkcs11_slot.js]
 [test_pkcs11_token.js]
 [test_pkcs11_tokenDB.js]
diff --git a/taskcluster/ci/test/test-sets.yml b/taskcluster/ci/test/test-sets.yml
index 99e929156db7..d6b48417130e 100644
--- a/taskcluster/ci/test/test-sets.yml
+++ b/taskcluster/ci/test/test-sets.yml
@@ -83,6 +83,7 @@ ccov-code-coverage-tests:
 jsdcov-code-coverage-tests:
     - mochitest-browser-chrome
     - mochitest-devtools-chrome
+    - xpcshell
 
 ##
 # Test sets still being greened up in various ways
diff --git a/taskcluster/ci/test/tests.yml b/taskcluster/ci/test/tests.yml
index d968e6c9fc47..1bb3ef02369b 100644
--- a/taskcluster/ci/test/tests.yml
+++ b/taskcluster/ci/test/tests.yml
@@ -1225,8 +1225,15 @@ web-platform-tests-wdspec:
 
 xpcshell:
     description: "xpcshell test run"
-    suite: xpcshell
+    suite:
+        by-test-platform:
+            linux64-jsdcov/opt: xpcshell-coverage
+            default: xpcshell
     treeherder-symbol: tc-X()
+    run-on-projects:
+        by-test-platform:
+            linux64-jsdcov/opt: []
+            default: ['all']
     chunks:
         by-test-platform:
             linux64/debug: 10
@@ -1270,4 +1277,8 @@ xpcshell:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
-                    - --xpcshell-suite=xpcshell
+                    by-test-platform:
+                        linux64-jsdcov/opt:
+                            - --xpcshell-suite=xpcshell-coverage
+                        default:
+                            - --xpcshell-suite=xpcshell
\ No newline at end of file
diff --git a/testing/mozharness/configs/unittests/linux_unittest.py b/testing/mozharness/configs/unittests/linux_unittest.py
index 304447ad8c07..1d88e652d19d 100644
--- a/testing/mozharness/configs/unittests/linux_unittest.py
+++ b/testing/mozharness/configs/unittests/linux_unittest.py
@@ -245,7 +245,8 @@ config = {
         },
         "xpcshell-coverage": {
             "options": ["--xpcshell=%(abs_app_dir)s/" + XPCSHELL_NAME,
-                        "--manifest=tests/xpcshell/tests/xpcshell.ini"],
+                        "--manifest=tests/xpcshell/tests/xpcshell.ini",
+                        "--sequential"],
             "tests": []
         },
     },
diff --git a/testing/xpcshell/head.js b/testing/xpcshell/head.js
index 446807316c8d..3fc55036b742 100644
--- a/testing/xpcshell/head.js
+++ b/testing/xpcshell/head.js
@@ -552,9 +552,6 @@ function _execute_test() {
     // has already been logged so there is no need to log it again. It's
     // possible that this will mask an NS_ERROR_ABORT that happens after a
     // do_check failure though.
-    if (coverageCollector != null) {
-      coverageCollector.recordTestCoverage(_TEST_FILE[0]);
-    }
 
     if (!_quit || e != Components.results.NS_ERROR_ABORT) {
       let extra = {};
@@ -572,10 +569,10 @@ function _execute_test() {
       }
       _testLogger.error(message, extra);
     }
-  }
-
-  if (coverageCollector != null) {
-    coverageCollector.finalize();
+  } finally {
+    if (coverageCollector != null) {
+      coverageCollector.finalize();
+    }
   }
 
   // Execute all of our cleanup functions.
diff --git a/testing/xpcshell/runxpcshelltests.py b/testing/xpcshell/runxpcshelltests.py
index 23155f3d5999..596a788c8192 100755
--- a/testing/xpcshell/runxpcshelltests.py
+++ b/testing/xpcshell/runxpcshelltests.py
@@ -1213,6 +1213,10 @@ class XPCShellTests(object):
 
         mozinfo.update(self.mozInfo)
 
+        # Add a flag to mozinfo to indicate that code coverage is enabled.
+        if self.jscovdir:
+            mozinfo.update({"coverage": True})
+
         self.stack_fixer_function = None
         if self.utility_path and os.path.exists(self.utility_path):
             self.stack_fixer_function = get_stack_fixer_function(self.utility_path, self.symbolsPath)
diff --git a/toolkit/components/jsdownloads/test/unit/xpcshell.ini b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
index d72e3fb1a0cd..19a6e8a5b1d0 100644
--- a/toolkit/components/jsdownloads/test/unit/xpcshell.ini
+++ b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
@@ -15,4 +15,5 @@ support-files =
 [test_Downloads.js]
 [test_DownloadStore.js]
 [test_PrivateTemp.js]
-skip-if = os != 'linux'
+# coverage flag is for bug 1336730
+skip-if = (os != 'linux' || coverage)
diff --git a/toolkit/components/osfile/tests/xpcshell/xpcshell.ini b/toolkit/components/osfile/tests/xpcshell/xpcshell.ini
index 6172fe6701e6..2f7a61cd7c39 100644
--- a/toolkit/components/osfile/tests/xpcshell/xpcshell.ini
+++ b/toolkit/components/osfile/tests/xpcshell/xpcshell.ini
@@ -47,4 +47,5 @@ requesttimeoutfactor = 4
 [test_reset.js]
 [test_shutdown.js]
 [test_telemetry.js]
+skip-if = coverage # bug 1336672
 [test_unique.js]
diff --git a/toolkit/components/startup/tests/unit/xpcshell.ini b/toolkit/components/startup/tests/unit/xpcshell.ini
index 809f9f3f6a39..daabb805ddf7 100644
--- a/toolkit/components/startup/tests/unit/xpcshell.ini
+++ b/toolkit/components/startup/tests/unit/xpcshell.ini
@@ -3,3 +3,4 @@ head = head_startup.js
 skip-if = toolkit == 'android'
 
 [test_startup_crash.js]
+skip-if = coverage # bug 1336673
diff --git a/tools/profiler/tests/xpcshell.ini b/tools/profiler/tests/xpcshell.ini
index cb322ae66beb..b014bd750c27 100644
--- a/tools/profiler/tests/xpcshell.ini
+++ b/tools/profiler/tests/xpcshell.ini
@@ -15,3 +15,4 @@ skip-if = !debug
 [test_enterjit_osr_enabling.js]
 skip-if = !debug
 [test_asm.js]
+skip-if = coverage # bug 1336674