diff -up ./src/3rdparty/chromium/build/config/compiler/BUILD.gn.xflag ./src/3rdparty/chromium/build/config/compiler/BUILD.gn
--- ./src/3rdparty/chromium/build/config/compiler/BUILD.gn.xflag	2025-05-29 10:27:28.000000000 +0900
+++ ./src/3rdparty/chromium/build/config/compiler/BUILD.gn	2026-05-13 20:21:10.372211198 +0900
@@ -492,6 +492,10 @@ config("compiler") {
         "_FILE_OFFSET_BITS=64",
         "_LARGEFILE_SOURCE",
         "_LARGEFILE64_SOURCE",
+        "_TIME_BITS=64",
+      ]
+      cflags += [
+        "-fcf-protection=none",
       ]
     }
 
diff -up ./src/3rdparty/chromium/third_party/libc++/src/CMakeLists.txt.xflag ./src/3rdparty/chromium/third_party/libc++/src/CMakeLists.txt
--- ./src/3rdparty/chromium/third_party/libc++/src/CMakeLists.txt.xflag	2025-05-29 10:27:28.000000000 +0900
+++ ./src/3rdparty/chromium/third_party/libc++/src/CMakeLists.txt	2026-05-13 20:21:10.373211200 +0900
@@ -826,6 +826,11 @@ if (WIN32 AND LIBCXX_ENABLE_STATIC_ABI_L
   add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
 endif()
 
+# i386 flags
+target_add_compile_flags_if_supported(${target} PUBLIC -fcf-protection=none)
+add_definitions(-D_TIME_BITS=64)
+add_definitions(-D_FILE_OFFSET_BITS=64)
+
 # Setup all common build flags =================================================
 function(cxx_add_common_build_flags target)
   cxx_add_basic_build_flags(${target})
diff -up ./src/core/api/CMakeLists.txt.xflag ./src/core/api/CMakeLists.txt
--- ./src/core/api/CMakeLists.txt.xflag	2025-05-29 10:27:28.000000000 +0900
+++ ./src/core/api/CMakeLists.txt	2026-05-14 17:14:01.105290915 +0900
@@ -47,6 +47,8 @@ qt_internal_add_module(WebEngineCore
     DEFINES
         BUILDING_CHROMIUM
         TOOLKIT_QT
+        _TIME_BITS=64
+        _FILE_OFFSET_BITS=64
     INCLUDE_DIRECTORIES
         ../
         ../../3rdparty/chromium