diff --git a/3rd/box2d/CMakeLists.txt b/3rd/box2d/CMakeLists.txt
index f768e9ed..e98e7298 100644
--- a/3rd/box2d/CMakeLists.txt
+++ b/3rd/box2d/CMakeLists.txt
@@ -14,7 +14,12 @@ aux_source_directory(${CMAKE_CURRENT_LIST_DIR}/src/rope BOX2D_SRC_3)
 
 aux_source_directory(${CMAKE_CURRENT_LIST_DIR}/src BOX2D_BINDINGS_SRC)
 
-set(CMAKE_CXX_FLAGS "-O2")
+if(MSVC)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /utf-8 /O2")
+else()
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions -O2")
+endif()
+
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 add_library(
diff --git a/3rd/cjson/CMakeLists.txt b/3rd/cjson/CMakeLists.txt
index 0142661b..748f1553 100644
--- a/3rd/cjson/CMakeLists.txt
+++ b/3rd/cjson/CMakeLists.txt
@@ -8,8 +8,14 @@ set(CMAKE_CXX_STANDARD 17)
 include_directories(${CMAKE_CURRENT_LIST_DIR}/include)
 include_directories(${CMAKE_CURRENT_LIST_DIR}/../pocketpy/include)
 
-set(CMAKE_C_FLAGS "-O2")
-set(CMAKE_CXX_FLAGS "-O2")
+if(MSVC)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /utf-8 /O2")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc /utf-8 /O2")
+else()
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O2")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fexceptions -O2")
+endif()
+
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 add_library(