diff --git a/taskcluster/taskgraph/transforms/repackage.py b/taskcluster/taskgraph/transforms/repackage.py
index ec1cec77217c..ffdfc7accf4c 100644
--- a/taskcluster/taskgraph/transforms/repackage.py
+++ b/taskcluster/taskgraph/transforms/repackage.py
@@ -82,7 +82,7 @@
 
 # The configuration passed to the mozharness repackage script. This defines the
 # arguments passed to `mach repackage`
-# - `args` is interpolated by mozharness (`{installer-tag}`,
+# - `args` is interpolated by mozharness (`{package-name}`, `{installer-tag}`,
 #   `{stub-installer-tag}`, `{sfx-stub}`) with values from the mozharness
 #   config.
 # - `inputs` are passed as long-options, with the filename prefixed by
@@ -117,7 +117,7 @@
     'installer': {
         'args': [
             "installer",
-            "--package-name", "firefox",
+            "--package-name", "{package-name}",
             "--tag", "{installer-tag}",
             "--sfx-stub", "{sfx-stub}",
         ],
diff --git a/testing/mozharness/configs/repackage/base.py b/testing/mozharness/configs/repackage/base.py
index 576938767a30..72b74f34af8a 100644
--- a/testing/mozharness/configs/repackage/base.py
+++ b/testing/mozharness/configs/repackage/base.py
@@ -1,4 +1,5 @@
 config = {
+    "package-name": "firefox",
     "installer-tag": "browser/installer/windows/app.tag",
     "stub-installer-tag": "browser/installer/windows/stub.tag",
     "sfx-stub": "other-licenses/7zstub/firefox/7zSD.sfx",
diff --git a/testing/mozharness/scripts/repackage.py b/testing/mozharness/scripts/repackage.py
index c53f57652c87..0f3e6ffac904 100644
--- a/testing/mozharness/scripts/repackage.py
+++ b/testing/mozharness/scripts/repackage.py
@@ -65,6 +65,7 @@ def repackage(self):
         dirs = self.query_abs_dirs()
 
         subst = {
+            'package-name': config['package-name'],
             'sfx-stub': config['sfx-stub'],
             'installer-tag': config['installer-tag'],
             'stub-installer-tag': config['stub-installer-tag'],