diff --git a/caps/BasePrincipal.cpp b/caps/BasePrincipal.cpp
index f32d628d0838..43d3c95f1a5c 100644
--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -106,21 +106,7 @@ BasePrincipal::GetOriginNoSuffix(nsACString& aOrigin) {
 NS_IMETHODIMP
 BasePrincipal::GetSiteOrigin(nsACString& aSiteOrigin) {
   MOZ_ASSERT(mInitialized);
-
-  nsresult rv = GetSiteOriginNoSuffix(aSiteOrigin);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  nsAutoCString suffix;
-  rv = GetOriginSuffix(suffix);
-  NS_ENSURE_SUCCESS(rv, rv);
-  aSiteOrigin.Append(suffix);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-BasePrincipal::GetSiteOriginNoSuffix(nsACString& aSiteOrigin) {
-  MOZ_ASSERT(mInitialized);
-  return GetOriginNoSuffix(aSiteOrigin);
+  return GetOrigin(aSiteOrigin);
 }
 
 // Returns the inner Json::value of the serialized principal
diff --git a/caps/BasePrincipal.h b/caps/BasePrincipal.h
index 8b414ad3e69e..450cd55f2adb 100644
--- a/caps/BasePrincipal.h
+++ b/caps/BasePrincipal.h
@@ -156,8 +156,7 @@ class BasePrincipal : public nsJSPrincipals {
       bool* aIsInIsolatedMozBrowserElement) final;
   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
-  NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) final;
-  NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
+  NS_IMETHOD GetSiteOrigin(nsACString& aOrigin) override;
   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
   NS_IMETHOD IsThirdPartyChannel(nsIChannel* aChannel, bool* aRes) override;
diff --git a/caps/ContentPrincipal.cpp b/caps/ContentPrincipal.cpp
index f8d6f03b5f53..e10379d32a83 100644
--- a/caps/ContentPrincipal.cpp
+++ b/caps/ContentPrincipal.cpp
@@ -440,7 +440,7 @@ ContentPrincipal::GetBaseDomain(nsACString& aBaseDomain) {
 }
 
 NS_IMETHODIMP
-ContentPrincipal::GetSiteOriginNoSuffix(nsACString& aSiteOrigin) {
+ContentPrincipal::GetSiteOrigin(nsACString& aSiteOrigin) {
   // Handle some special URIs first.
   nsAutoCString baseDomain;
   bool handled;
@@ -450,7 +450,7 @@ ContentPrincipal::GetSiteOriginNoSuffix(nsACString& aSiteOrigin) {
   if (handled) {
     // This is a special URI ("file:", "about:", "view-source:", etc). Just
     // return the origin.
-    return GetSiteOriginNoSuffix(aSiteOrigin);
+    return GetOrigin(aSiteOrigin);
   }
 
   // For everything else, we ask the TLD service. Note that, unlike in
@@ -491,7 +491,15 @@ ContentPrincipal::GetSiteOriginNoSuffix(nsACString& aSiteOrigin) {
 
   rv = GenerateOriginNoSuffixFromURI(siteUri, aSiteOrigin);
   MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to create siteOriginNoSuffix");
-  return rv;
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString suffix;
+  rv = GetOriginSuffix(suffix);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to create suffix");
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aSiteOrigin.Append(suffix);
+  return NS_OK;
 }
 
 nsresult ContentPrincipal::GetSiteIdentifier(SiteIdentifier& aSite) {
diff --git a/caps/ContentPrincipal.h b/caps/ContentPrincipal.h
index 2c7aac3c0b7e..ec4fc7cedacd 100644
--- a/caps/ContentPrincipal.h
+++ b/caps/ContentPrincipal.h
@@ -30,7 +30,7 @@ class ContentPrincipal final : public BasePrincipal {
   NS_IMETHOD SetDomain(nsIURI* aDomain) override;
   NS_IMETHOD GetBaseDomain(nsACString& aBaseDomain) override;
   NS_IMETHOD GetAddonId(nsAString& aAddonId) override;
-  NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
+  NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) override;
   bool IsContentPrincipal() const override { return true; }
 
   ContentPrincipal();
diff --git a/caps/nsIPrincipal.idl b/caps/nsIPrincipal.idl
index 3f756f38c78b..5332259a4320 100644
--- a/caps/nsIPrincipal.idl
+++ b/caps/nsIPrincipal.idl
@@ -419,15 +419,10 @@ interface nsIPrincipal : nsISerializable
      * principals which allow mutating |domain|, such as ContentPrincipal,
      * override the default implementation in BasePrincipal.
      *
+     * TODO(nika): Use this in DocGroup.
      */
     readonly attribute ACString siteOrigin;
 
-    /**
-     * The base part of |siteOrigin| without the concatenation with
-     * |originSuffix|.
-     */
-    readonly attribute ACString siteOriginNoSuffix;
-
     /**
      * The base domain of the principal URI to which this principal pertains
      * (generally the document URI), handling null principals and