diff --git a/dom/base/nsGlobalWindowInner.cpp b/dom/base/nsGlobalWindowInner.cpp
index b6fe6a09eb41..077bd123fdf5 100644
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -1626,6 +1626,13 @@ OriginTrials nsGlobalWindowInner::Trials() const {
   return OriginTrials::FromWindow(this);
 }
 
+FontFaceSet* nsGlobalWindowInner::Fonts() {
+  if (mDoc) {
+    return mDoc->Fonts();
+  }
+  return nullptr;
+}
+
 uint32_t nsGlobalWindowInner::GetPrincipalHashValue() const {
   if (mDoc) {
     return mDoc->NodePrincipal()->GetHashValue();
diff --git a/dom/base/nsGlobalWindowInner.h b/dom/base/nsGlobalWindowInner.h
index e8c3ad5ffc7c..b57ef24043c5 100644
--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -249,6 +249,7 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
   bool ShouldResistFingerprinting() const final;
   uint32_t GetPrincipalHashValue() const final;
   mozilla::OriginTrials Trials() const final;
+  mozilla::dom::FontFaceSet* Fonts() final;
 
   JSObject* GetGlobalJSObject() final { return GetWrapper(); }
   JSObject* GetGlobalJSObjectPreserveColor() const final {
diff --git a/dom/base/nsGlobalWindowOuter.cpp b/dom/base/nsGlobalWindowOuter.cpp
index 674353189dca..2337f4ef0091 100644
--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@@ -1683,6 +1683,13 @@ OriginTrials nsGlobalWindowOuter::Trials() const {
                       : OriginTrials();
 }
 
+FontFaceSet* nsGlobalWindowOuter::Fonts() {
+  if (mDoc) {
+    return mDoc->Fonts();
+  }
+  return nullptr;
+}
+
 nsresult nsGlobalWindowOuter::EnsureScriptEnvironment() {
   if (GetWrapperPreserveColor()) {
     return NS_OK;
diff --git a/dom/base/nsGlobalWindowOuter.h b/dom/base/nsGlobalWindowOuter.h
index 70cea10edfd5..be253c9efd07 100644
--- a/dom/base/nsGlobalWindowOuter.h
+++ b/dom/base/nsGlobalWindowOuter.h
@@ -235,6 +235,7 @@ class nsGlobalWindowOuter final : public mozilla::dom::EventTarget,
   bool ShouldResistFingerprinting() const final;
   uint32_t GetPrincipalHashValue() const final;
   mozilla::OriginTrials Trials() const final;
+  mozilla::dom::FontFaceSet* Fonts() final;
 
   // nsIGlobalJSObjectHolder
   JSObject* GetGlobalJSObject() final { return GetWrapper(); }
diff --git a/dom/base/nsIGlobalObject.h b/dom/base/nsIGlobalObject.h
index 9d10ad58d843..fc57a642ee5a 100644
--- a/dom/base/nsIGlobalObject.h
+++ b/dom/base/nsIGlobalObject.h
@@ -38,6 +38,7 @@ enum class StorageAccess;
 namespace dom {
 class VoidFunction;
 class DebuggerNotificationManager;
+class FontFaceSet;
 class Function;
 class Report;
 class ReportBody;
@@ -252,6 +253,8 @@ class nsIGlobalObject : public nsISupports,
     return nullptr;
   }
 
+  virtual mozilla::dom::FontFaceSet* Fonts() { return nullptr; }
+
  protected:
   virtual ~nsIGlobalObject();
 
diff --git a/layout/style/FontFace.cpp b/layout/style/FontFace.cpp
index 972739105707..5cb960868479 100644
--- a/layout/style/FontFace.cpp
+++ b/layout/style/FontFace.cpp
@@ -20,7 +20,6 @@
 #include "mozilla/ServoStyleSet.h"
 #include "mozilla/ServoUtils.h"
 #include "mozilla/StaticPrefs_layout.h"
-#include "mozilla/dom/Document.h"
 #include "nsStyleUtil.h"
 
 namespace mozilla {
@@ -72,7 +71,7 @@ NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(FontFace)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(FontFace)
 
-FontFace::FontFace(nsISupports* aParent)
+FontFace::FontFace(nsIGlobalObject* aParent)
     : mParent(aParent), mLoadedRejection(NS_OK) {}
 
 FontFace::~FontFace() {
@@ -90,7 +89,7 @@ JSObject* FontFace::WrapObject(JSContext* aCx,
 }
 
 already_AddRefed<FontFace> FontFace::CreateForRule(
-    nsISupports* aGlobal, FontFaceSet* aFontFaceSet,
+    nsIGlobalObject* aGlobal, FontFaceSet* aFontFaceSet,
     RawServoFontFaceRule* aRule) {
   FontFaceSetImpl* setImpl = aFontFaceSet->GetImpl();
   MOZ_ASSERT(setImpl);
@@ -104,22 +103,20 @@ already_AddRefed<FontFace> FontFace::Constructor(
     const GlobalObject& aGlobal, const nsACString& aFamily,
     const UTF8StringOrArrayBufferOrArrayBufferView& aSource,
     const FontFaceDescriptors& aDescriptors, ErrorResult& aRv) {
-  nsISupports* global = aGlobal.GetAsSupports();
-  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(global);
-  if (!window) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
+
+  FontFaceSet* set = global->Fonts();
+  if (!set) {
     aRv.Throw(NS_ERROR_FAILURE);
     return nullptr;
   }
 
-  Document* doc = window->GetDoc();
-  if (!doc) {
+  FontFaceSetImpl* setImpl = set->GetImpl();
+  if (!setImpl) {
     aRv.Throw(NS_ERROR_FAILURE);
     return nullptr;
   }
 
-  FontFaceSetImpl* setImpl = doc->Fonts()->GetImpl();
-  MOZ_ASSERT(setImpl);
-
   RefPtr<FontFace> obj = new FontFace(global);
   obj->mImpl = new FontFaceImpl(obj, setImpl);
   if (!obj->mImpl->SetDescriptors(aFamily, aDescriptors)) {
@@ -321,18 +318,16 @@ already_AddRefed<URLExtraData> FontFace::GetURLExtraData() const {
 void FontFace::EnsurePromise() {
   MOZ_ASSERT(NS_IsMainThread());
 
-  if (mLoaded || !mImpl) {
+  if (mLoaded || !mImpl || !mParent) {
     return;
   }
 
-  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(mParent);
-
   // If the pref is not set, don't create the Promise (which the page wouldn't
   // be able to get to anyway) as it causes the window.FontFace constructor
   // to be created.
-  if (global && FontFaceSet::PrefEnabled()) {
+  if (FontFaceSet::PrefEnabled()) {
     ErrorResult rv;
-    mLoaded = Promise::Create(global, rv);
+    mLoaded = Promise::Create(mParent, rv);
 
     if (mImpl->Status() == FontFaceLoadStatus::Loaded) {
       mLoaded->MaybeResolve(this);
diff --git a/layout/style/FontFace.h b/layout/style/FontFace.h
index 855395c3641d..499e9c7d48e8 100644
--- a/layout/style/FontFace.h
+++ b/layout/style/FontFace.h
@@ -43,11 +43,11 @@ class FontFace final : public nsISupports, public nsWrapperCache {
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(FontFace)
 
-  nsISupports* GetParentObject() const { return mParent; }
+  nsIGlobalObject* GetParentObject() const { return mParent; }
   virtual JSObject* WrapObject(JSContext* aCx,
                                JS::Handle<JSObject*> aGivenProto) override;
 
-  static already_AddRefed<FontFace> CreateForRule(nsISupports* aGlobal,
+  static already_AddRefed<FontFace> CreateForRule(nsIGlobalObject* aGlobal,
                                                   FontFaceSet* aFontFaceSet,
                                                   RawServoFontFaceRule* aRule);
 
@@ -97,7 +97,7 @@ class FontFace final : public nsISupports, public nsWrapperCache {
   already_AddRefed<URLExtraData> GetURLExtraData() const;
 
  private:
-  explicit FontFace(nsISupports* aParent);
+  explicit FontFace(nsIGlobalObject* aParent);
   ~FontFace();
 
   /**
@@ -109,7 +109,7 @@ class FontFace final : public nsISupports, public nsWrapperCache {
   // reject mLoaded based on mStatus and mLoadedRejection.
   void EnsurePromise();
 
-  nsCOMPtr<nsISupports> mParent;
+  nsCOMPtr<nsIGlobalObject> mParent;
 
   RefPtr<FontFaceImpl> mImpl;