diff --git a/browser/branding/aurora/branding.nsi b/browser/branding/aurora/branding.nsi
index fa2ef778d78f..b6e122dc369f 100644
--- a/browser/branding/aurora/branding.nsi
+++ b/browser/branding/aurora/branding.nsi
@@ -10,6 +10,7 @@
 # instead of BrandFullName and typically should not be modified.
 !define BrandFullNameInternal "Firefox Developer Edition"
 !define BrandShortName        "Firefox Developer Edition"
+!define BrandFullName         "Firefox Developer Edition"
 !define CompanyName           "mozilla.org"
 !define URLInfoAbout          "https://www.mozilla.org"
 !define HelpLink              "https://support.mozilla.org"
diff --git a/browser/branding/official/branding.nsi b/browser/branding/official/branding.nsi
index a6025a326d5c..ba248218e74c 100644
--- a/browser/branding/official/branding.nsi
+++ b/browser/branding/official/branding.nsi
@@ -9,6 +9,7 @@
 # BrandFullNameInternal is used for some registry and file system values
 # instead of BrandFullName and typically should not be modified.
 !define BrandFullNameInternal "Mozilla Firefox"
+!define BrandFullName         "Mozilla Firefox"
 !define CompanyName           "Mozilla Corporation"
 !define URLInfoAbout          "https://www.mozilla.org"
 !define URLUpdateInfo         "https://www.mozilla.org/firefox/${AppVersion}/releasenotes"
diff --git a/browser/branding/unofficial/branding.nsi b/browser/branding/unofficial/branding.nsi
index 8a81823311fe..257507542126 100644
--- a/browser/branding/unofficial/branding.nsi
+++ b/browser/branding/unofficial/branding.nsi
@@ -9,6 +9,7 @@
 # BrandFullNameInternal is used for some registry and file system values
 # instead of BrandFullName and typically should not be modified.
 !define BrandFullNameInternal "Mozilla Developer Preview"
+!define BrandFullName         "Mozilla Developer Preview"
 !define CompanyName           "mozilla.org"
 !define URLInfoAbout          "https://www.mozilla.org"
 !define HelpLink              "https://support.mozilla.org"
diff --git a/browser/installer/windows/nsis/defines.nsi.in b/browser/installer/windows/nsis/defines.nsi.in
index 3626da45d493..67d973d1b7f8 100644
--- a/browser/installer/windows/nsis/defines.nsi.in
+++ b/browser/installer/windows/nsis/defines.nsi.in
@@ -36,7 +36,9 @@
 !ifndef DEV_EDITION
 !define BrandShortName        "@MOZ_APP_DISPLAYNAME@"
 !endif
+!ifndef BrandFullName
 !define BrandFullName         "${BrandFullNameInternal}"
+!endif
 
 !define CERTIFICATE_NAME            "Mozilla Corporation"
 !define CERTIFICATE_ISSUER          "DigiCert SHA2 Assured ID Code Signing CA"
diff --git a/browser/installer/windows/nsis/maintenanceservice_installer.nsi b/browser/installer/windows/nsis/maintenanceservice_installer.nsi
index 9535a00c70a8..26a044115798 100644
--- a/browser/installer/windows/nsis/maintenanceservice_installer.nsi
+++ b/browser/installer/windows/nsis/maintenanceservice_installer.nsi
@@ -51,7 +51,9 @@ Var BrandFullName
 ; We keep defines.nsi defined so that we get other things like 
 ; the version number, but we redefine BrandFullName
 !define MaintFullName "Mozilla Maintenance Service"
+!ifdef BrandFullName
 !undef BrandFullName
+!endif
 !define BrandFullName "${MaintFullName}"
 
 !include common.nsh
diff --git a/toolkit/components/maintenanceservice/bootstrapinstaller/maintenanceservice_installer.nsi b/toolkit/components/maintenanceservice/bootstrapinstaller/maintenanceservice_installer.nsi
index fa52234be7e3..98701fff542e 100644
--- a/toolkit/components/maintenanceservice/bootstrapinstaller/maintenanceservice_installer.nsi
+++ b/toolkit/components/maintenanceservice/bootstrapinstaller/maintenanceservice_installer.nsi
@@ -51,7 +51,9 @@ Var BrandFullName
 ; We keep defines.nsi defined so that we get other things like 
 ; the version number, but we redefine BrandFullName
 !define MaintFullName "Mozilla Maintenance Service"
+!ifdef BrandFullName
 !undef BrandFullName
+!endif
 !define BrandFullName "${MaintFullName}"
 
 !include common.nsh