diff --git a/CMakeLists.txt b/CMakeLists.txt
index 25289a774..a7de2cdb0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -82,8 +82,8 @@ if (EMSCRIPTEN)
   set(ZLIB_LIBRARIES)
   set(ZLIB_INCLUDE_DIR)
 
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Os -s ALLOW_MEMORY_GROWTH=1 -s USE_ZLIB=1 -s MODULARIZE=1 -s WEBSOCKET_URL=\"'wss:#'\" -s EXTRA_EXPORTED_RUNTIME_METHODS=\"['FS','cwrap']\"")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Os -s ALLOW_MEMORY_GROWTH=1 -s USE_ZLIB=1 -s MODULARIZE=1 -s WEBSOCKET_URL=\"'wss:#'\" -s EXTRA_EXPORTED_RUNTIME_METHODS=\"['FS','cwrap']\"")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Os -s ALLOW_MEMORY_GROWTH=1 -s MEMFS_APPEND_TO_TYPED_ARRAYS=1 -s USE_ZLIB=1 -s MODULARIZE=1 -s WEBSOCKET_URL=\"'wss:#'\" -s EXTRA_EXPORTED_RUNTIME_METHODS=\"['FS','cwrap']\"")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Os -s ALLOW_MEMORY_GROWTH=1 -s MEMFS_APPEND_TO_TYPED_ARRAYS=1 -s USE_ZLIB=1 -s MODULARIZE=1 -s WEBSOCKET_URL=\"'wss:#'\" -s EXTRA_EXPORTED_RUNTIME_METHODS=\"['FS','cwrap']\"")
   set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=1")
   set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=1")