diff --git a/patches/roverfox/font-fingerprinting.context.patch b/patches/roverfox/font-fingerprinting.context.patch
index a2c283b4..9009e72d 100644
--- a/patches/roverfox/font-fingerprinting.context.patch
+++ b/patches/roverfox/font-fingerprinting.context.patch
@@ -869,25 +869,25 @@ index a8fac45e67..d59815f2d5 100644
  
    EmphasisMarkDrawParams params(aContext, aPaletteCache);
    params.mark = aMark;
-@@ -1861,7 +1865,8 @@ gfxFontGroup::gfxFontGroup(nsPresContext* aPresContext,
-       mPageLang(gfxPlatformFontList::GetFontPrefLangFor(aLanguage)),
-       mLastPrefFirstFont(false),
-       mSkipDrawing(false),
--      mExplicitLanguage(aExplicitLanguage) {
-+      mExplicitLanguage(aExplicitLanguage),
+@@ -1873,2 +1877,3 @@ gfxFontGroup::gfxFontGroup(FontVisibilityProvider* aFontVisibilityProvider,
+      mPageLang(gfxPlatformFontList::GetFontPrefLangFor(aLanguage)),
+      mExplicitLanguage(aExplicitLanguage),
+-      mFontVariantEmoji(aVariantEmoji) {
++      mFontVariantEmoji(aVariantEmoji),
++      mUserContextId(0) {
 +      mUserContextId(0) {
    switch (aVariantEmoji) {
      case StyleFontVariantEmoji::Normal:
      case StyleFontVariantEmoji::Unicode:
-@@ -1876,6 +1881,19 @@ gfxFontGroup::gfxFontGroup(nsPresContext* aPresContext,
+@@ -1875,4 +1880,17 @@ gfxFontGroup::gfxFontGroup(FontVisibilityProvider* aFontVisibilityProvider,
    // We don't use SetUserFontSet() here, as we want to unconditionally call
    // EnsureFontList() rather than only do UpdateUserFonts() if it changed.
    mCurrGeneration = 0;
 +
 +  // Initialize cached user context ID from the document principal.
 +  mUserContextId = 0;
-+  if (mPresContext) {
-+    if (auto* doc = mPresContext->Document()) {
++  if (mFontVisibilityProvider) {
+    if (auto* doc = mFontVisibilityProvider ? mFontVisibilityProvider->GetDocument() : nullptr) {
 +      if (auto* principal = doc->NodePrincipal()) {
 +        auto* bp = mozilla::BasePrincipal::Cast(principal);
 +        if (bp) {