--- a/layout/style/FontFaceSet.cpp
+++ b/layout/style/FontFaceSet.cpp
@@ -442,16 +442,23 @@ FontFaceSet::StartLoad(gfxUserFontEntry*
   if (httpChannel) {
     httpChannel->SetReferrer(aFontFaceSrc->mReferrer);
     nsAutoCString accept("application/font-woff;q=0.9,*/*;q=0.8");
     if (Preferences::GetBool(GFX_PREF_WOFF2_ENABLED)) {
       accept.Insert(NS_LITERAL_CSTRING("application/font-woff2;q=1.0,"), 0);
     }
     httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("Accept"),
                                   accept, false);
+    // For WOFF and WOFF2, we should tell servers/proxies/etc NOT to try
+    // and apply additional compression at the content-encoding layer
+    if (aFontFaceSrc->mFormatFlags & (gfxUserFontSet::FLAG_FORMAT_WOFF |
+                                      gfxUserFontSet::FLAG_FORMAT_WOFF2)) {
+      httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("Accept-Encoding"),
+                                    NS_LITERAL_CSTRING("identity"), false);
+    }
   }
   nsCOMPtr<nsISupportsPriority> priorityChannel(do_QueryInterface(channel));
   if (priorityChannel) {
     priorityChannel->AdjustPriority(nsISupportsPriority::PRIORITY_HIGH);
   }
 
   rv = NS_NewStreamLoader(getter_AddRefs(streamLoader), fontLoader);
   NS_ENSURE_SUCCESS(rv, rv);