diff --git a/cef.spec b/cef.spec
index 8b515e1..2f67c9c 100644
--- a/cef.spec
+++ b/cef.spec
@@ -19,6 +19,13 @@
 # official builds have less debugging and go faster... but we have to shut some things off.
 %global official_build 1
 
+# enable|disble use_custom_libcxx
+%global use_custom_libcxx 0
+%if 0%{?rhel}
+# no libcxx in el
+%global use_custom_libcxx 1
+%endif
+
 # enable|disble bootstrap
 %global bootstrap 0
 # workaround for old gn on el9, it causes build error: unknown function filter_labels_include()
@@ -141,9 +148,6 @@
 
 # enable|disable control flow integrity support
 %global cfi 0
-%ifarch x86_64
-%global cfi 0
-%endif
 
 ## CEF: QT builds are not relevant
 %global use_qt6 0
@@ -256,6 +260,9 @@ Patch20: chromium-disable-font-tests.patch
 # don't download binary blob
 Patch21: chromium-123-screen-ai-service.patch
 
+# Fix link error when building with system libcxx
+Patch22: chromium-131-fix-qt-ui.pach
+
 # Disable tests on remoting build
 Patch82: chromium-98.0.4758.102-remoting-no-tests.patch
 
@@ -349,6 +356,8 @@ Patch316: chromium-122-clang-build-flags.patch
 # unknown warning option -Wno-nontrivial-memcall
 Patch317: chromium-142-clang++-unknown-argument.patch
 
+Patch318: memory-allocator-dcheck-assert-fix.patch
+
 # Workaround for https://bugzilla.redhat.com/show_bug.cgi?id=2239523
 # https://bugs.chromium.org/p/chromium/issues/detail?id=1145581#c60
 # Disable BTI until this is fixed upstream.
@@ -416,7 +425,6 @@ Patch402: fix-rust-linking.patch
 Patch403: fix-breakpad-compile.patch
 Patch404: fix-partition-alloc-compile.patch
 Patch405: fix-study-crash.patch
-Patch406: memory-allocator-dcheck-assert-fix.patch
 Patch407: fix-different-data-layouts.patch
 Patch408: 0002-Add-ppc64-trap-instructions.patch
 
@@ -496,6 +504,10 @@ BuildRequires: clang-tools-extra
 BuildRequires: llvm
 BuildRequires: lld
 
+%if ! %{use_custom_libcxx}
+BuildRequires: libcxx-devel
+%endif
+
 %if 0%{?rhel} && 0%{?rhel} <= 9
 BuildRequires: gcc-toolset-14-libatomic-devel
 %endif
@@ -939,6 +951,9 @@ mv %{_builddir}/cef-%{cef_commit} ./cef
 
 %patch -P20 -p1 -b .disable-font-test
 %patch -P21 -p1 -b .screen-ai-service
+%if ! %{use_custom_libcxx}
+%patch -P22 -p1 -b .fix-qt-ui
+%endif
 
 %patch -P82 -p1 -b .remoting-no-tests
 
@@ -1017,6 +1032,8 @@ mv %{_builddir}/cef-%{cef_commit} ./cef
 %patch -P317 -p1 -b .clang++-unsupported-argument
 %endif
 
+%patch -P318 -p1 -b .memory-allocator-dcheck-assert-fix
+
 %if %{disable_bti}
 %patch -P352 -p1 -b .workaround_for_crash_on_BTI_capable_system
 %endif
@@ -1063,7 +1080,6 @@ mv %{_builddir}/cef-%{cef_commit} ./cef
 %patch -P403 -p1 -b .fix-breakpad-compile
 %patch -P404 -p1 -b .fix-partition-alloc-compile
 %patch -P405 -p1 -b .fix-study-crash
-%patch -P406 -p1 -b .memory-allocator-dcheck-assert-fix
 %patch -P407 -p1 -b .fix-different-data-layouts
 %patch -P408 -p1 -b .0002-Add-ppc64-trap-instructions
 %patch -P409 -p1 -b .fix-page-allocator-overflow
@@ -1229,6 +1245,11 @@ CXXFLAGS="$FLAGS"
 CXXFLAGS+=' -faltivec-src-compat=mixed -Wno-deprecated-altivec-src-compat'
 %endif
 
+%if ! %{use_custom_libcxx}
+LDFLAGS="${LDFLAGS} -stdlib=libc++"
+CXXFLAGS="${CXXFLAGS} -stdlib=libc++"
+%endif
+
 export CC=clang
 export CXX=clang++
 export AR=llvm-ar
@@ -1236,6 +1257,7 @@ export NM=llvm-nm
 export READELF=llvm-readelf
 export CFLAGS
 export CXXFLAGS
+export LDFLAGS
 
 # need for error: the option `Z` is only accepted on the nightly compiler
 export RUSTC_BOOTSTRAP=1
@@ -1259,6 +1281,9 @@ CHROMIUM_CORE_GN_DEFINES=""
 # using system toolchain
 CHROMIUM_CORE_GN_DEFINES+=' custom_toolchain="//build/toolchain/linux/unbundle:default"'
 CHROMIUM_CORE_GN_DEFINES+=' host_toolchain="//build/toolchain/linux/unbundle:default"'
+%if ! %{use_custom_libcxx}
+CHROMIUM_BROWSER_GN_DEFINES+=' use_custom_libcxx=false'
+%endif
 CHROMIUM_CORE_GN_DEFINES+=' is_debug=false dcheck_always_on=false dcheck_is_configurable=false'
 CHROMIUM_CORE_GN_DEFINES+=' enable_enterprise_companion=false'
 CHROMIUM_CORE_GN_DEFINES+=' system_libdir="%{_lib}"'
@@ -1307,10 +1332,7 @@ CHROMIUM_CORE_GN_DEFINES+=' symbol_level=%{debug_level} blink_symbol_level=%{deb
 CHROMIUM_CORE_GN_DEFINES+=' angle_has_histograms=false'
 # drop unrar
 CHROMIUM_CORE_GN_DEFINES+=' safe_browsing_use_unrar=false'
-# Disable --warning-suppression-mappings as it causes FTBFS on el/f40/f41 due to old llvm
-%if 0%{?rhel} || 0%{?fedora} == 40 || 0%{?fedora} == 41
-CHROMIUM_CORE_GN_DEFINES+=' clang_warning_suppression_file=""'
-%endif
+CHROMIUM_CORE_GN_DEFINES+=' v8_enable_backtrace=true'
 export CHROMIUM_CORE_GN_DEFINES
 
 # browser gn defines
diff --git a/chromium-131-fix-qt-ui.pach b/chromium-131-fix-qt-ui.pach
new file mode 100644
index 0000000..d0b778c
--- /dev/null
+++ b/chromium-131-fix-qt-ui.pach
@@ -0,0 +1,19 @@
+From b9075d0e1f687f9a5cf80a7778bde99cece9fdf7 Mon Sep 17 00:00:00 2001
+From: Than Ngo <than@redhat.com>
+Date: Sat, 23 Nov 2024 12:33:22 +0100
+Subject: [PATCH] Enable qt-ui
+
+
+diff -up chromium-131.0.6778.85/ui/qt/qt_shim.cc.me chromium-131.0.6778.85/ui/qt/qt_shim.cc
+--- chromium-131.0.6778.85/ui/qt/qt_shim.cc.me	2024-11-23 10:04:16.789121846 +0100
++++ chromium-131.0.6778.85/ui/qt/qt_shim.cc	2024-11-23 11:40:02.905064702 +0100
+@@ -265,7 +265,7 @@ FontRenderParams QtShim::GetFontRenderPa
+ FontDescription QtShim::GetFontDescription() const {
+   QFont font = app_.font();
+   return {
+-      .family = String(font.family().toStdString().c_str()),
++      .family = String(font.family().toUtf8().constData()),
+       .size_pixels = font.pixelSize(),
+       .size_points = font.pointSize(),
+       .is_italic = IsStyleItalic(font.style()),
+