--- a/testing/mozharness/configs/builds/branch_specifics.py
+++ b/testing/mozharness/configs/builds/branch_specifics.py
@@ -179,16 +179,91 @@ config = {
             'win32-mulet': {
                 'update_channel': 'default',
             },
             'win64-debug': {
                 'update_channel': 'default',
             },
         },
     },
+    'mozilla-esr45': {
+        'enable_release_promotion': True,
+        'repo_path': 'releases/mozilla-esr45',
+        'update_channel': 'esr',
+        'branch_uses_per_checkin_strategy': True,
+        'use_branch_in_symbols_extra_buildid': False,
+        'stage_server': 'upload.ffxbld.productdelivery.prod.mozaws.net',
+        'platform_overrides': {
+            'linux': {
+                'src_mozconfig': 'browser/config/mozconfigs/linux32/release',
+                'force_clobber': True,
+            },
+            'linux64': {
+                'src_mozconfig': 'browser/config/mozconfigs/linux64/release',
+                'force_clobber': True,
+            },
+            'macosx64': {
+                'src_mozconfig': 'browser/config/mozconfigs/macosx-universal/release',
+                'force_clobber': True,
+            },
+            'win32': {
+                'src_mozconfig': 'browser/config/mozconfigs/win32/release',
+                'force_clobber': True,
+            },
+            'win64': {
+                'src_mozconfig': 'browser/config/mozconfigs/win64/release',
+                'force_clobber': True,
+            },
+            'linux-debug': {
+                'update_channel': 'default',
+            },
+            'linux64-debug': {
+                'update_channel': 'default',
+            },
+            'linux64-asan-debug': {
+                'update_channel': 'default',
+            },
+            'linux64-asan': {
+                'update_channel': 'default',
+            },
+            'linux64-cc': {
+                'update_channel': 'default',
+            },
+            'linux64-st-an-debug': {
+                'update_channel': 'default',
+            },
+            'linux64-st-an': {
+                'update_channel': 'default',
+            },
+            'linux64-tsan': {
+                'update_channel': 'default',
+            },
+            'macosx64-debug': {
+                'update_channel': 'default',
+            },
+            'macosx64-st-an': {
+                'update_channel': 'default',
+            },
+            'macosx64-mulet': {
+                'update_channel': 'default',
+            },
+            'macosx64-st-an-debug': {
+                'update_channel': 'default',
+            },
+            'win32-debug': {
+                'update_channel': 'default',
+            },
+            'win32-mulet': {
+                'update_channel': 'default',
+            },
+            'win64-debug': {
+                'update_channel': 'default',
+            },
+        },
+    },
     'mozilla-aurora': {
         'repo_path': 'releases/mozilla-aurora',
         'update_channel': 'aurora',
         'branch_uses_per_checkin_strategy': True,
         'stage_server': 'upload.ffxbld.productdelivery.prod.mozaws.net',
     },
     'try': {
         'repo_path': 'try',

new file mode 100644
--- /dev/null
+++ b/testing/mozharness/configs/releases/postrelease_firefox_esr45.py
@@ -0,0 +1,18 @@
+config = {
+    "log_name": "bump_esr45",
+    "version_files": [
+        {"file": "browser/config/version.txt"},
+        {"file": "browser/config/version_display.txt"},
+        {"file": "config/milestone.txt"},
+    ],
+    "repo": {
+        "repo": "https://hg.mozilla.org/releases/mozilla-esr45",
+        "revision": "default",
+        "dest": "mozilla-esr45",
+        "vcs": "hg",
+    },
+    "push_dest": "ssh://hg.mozilla.org/releases/mozilla-esr45",
+    "ignore_no_changes": True,
+    "ssh_user": "ffxbld",
+    "ssh_key": "~/.ssh/ffxbld_rsa",
+}

new file mode 100644
--- /dev/null
+++ b/testing/mozharness/configs/releases/updates_firefox_esr45.py
@@ -0,0 +1,34 @@
+
+config = {
+    "log_name": "updates_esr45",
+    "repo": {
+        "repo": "https://hg.mozilla.org/build/tools",
+        "revision": "default",
+        "dest": "tools",
+        "vcs": "hg",
+    },
+    "push_dest": "ssh://hg.mozilla.org/build/tools",
+    "shipped-locales-url": "https://hg.mozilla.org/releases/mozilla-esr45/raw-file/{revision}/browser/locales/shipped-locales",
+    "ignore_no_changes": True,
+    "ssh_user": "ffxbld",
+    "ssh_key": "~/.ssh/ffxbld_rsa",
+    "archive_domain": "archive.mozilla.org",
+    "archive_prefix": "https://archive.mozilla.org/pub",
+    "previous_archive_prefix": "https://archive.mozilla.org/pub",
+    "download_domain": "download.mozilla.org",
+    "balrog_url": "https://aus5.mozilla.org",
+    "balrog_username": "ffxbld",
+    "update_channels": {
+        "esr": {
+            "version_regex": r".*",
+            "requires_mirrors": True,
+            "patcher_config": "mozEsr45-branch-patcher2.cfg",
+            "update_verify_channel": "esr-localtest",
+            "mar_channel_ids": [],
+            "channel_names": ["esr", "esr-localtest", "esr-cdntest"],
+            "rules_to_update": ["esr45-cdntest", "esr45-localtest"],
+            "publish_rules": ["esr"],
+        },
+    },
+    "balrog_use_dummy_suffix": False,
+}

new file mode 100644
--- /dev/null
+++ b/testing/mozharness/configs/single_locale/mozilla-esr45.py
@@ -0,0 +1,40 @@
+config = {
+    "nightly_build": True,
+    "branch": "mozilla-esr45",
+    "en_us_binary_url": "http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla-esr45/",
+    "update_channel": "esr",
+    "latest_mar_dir": '/pub/mozilla.org/firefox/nightly/latest-mozilla-esr45-l10n',
+
+    # l10n
+    "hg_l10n_base": "https://hg.mozilla.org/releases/l10n/mozilla-release",
+
+    # repositories
+    "mozilla_dir": "mozilla-esr45",
+    "repos": [{
+        "vcs": "hg",
+        "repo": "https://hg.mozilla.org/build/tools",
+        "revision": "default",
+        "dest": "tools",
+    }, {
+        "vcs": "hgtool",
+        "repo": "https://hg.mozilla.org/releases/mozilla-esr45",
+        "revision": "default",
+        "dest": "mozilla-esr45",
+    }, {
+        "vcs": "hgtool",
+        "repo": "https://hg.mozilla.org/build/compare-locales",
+        "revision": "RELEASE_AUTOMATION"
+    }],
+    # purge options
+    'purge_minsize': 12,
+    'is_automation': True,
+    'default_actions': [
+        "clobber",
+        "pull",
+        "list-locales",
+        "setup",
+        "repack",
+        "taskcluster-upload",
+        "summary",
+    ],
+}