diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a9dbce9f..329f0bcf 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -25,8 +25,12 @@ jobs:
     - uses: mymindstorm/setup-emsdk@v11
     - name: Compiling
       run: |
-        bash build_wasm.sh
         mkdir -p output/web/lib
+        mkdir -p output/web/lib_pthread
+        bash build_wasm.sh
+        mv web/lib/* output/web/lib_pthread
+        export PTHREAD_FLAG=" "
+        bash build_wasm.sh
         cp web/lib/* output/web/lib
     - uses: crazy-max/ghaction-github-pages@v3
       with:
diff --git a/build_wasm.sh b/build_wasm.sh
index 1a78dc33..4975bdd2 100644
--- a/build_wasm.sh
+++ b/build_wasm.sh
@@ -1,3 +1,3 @@
 rm -rf web/lib/
 mkdir -p web/lib/
-em++ src/main.cpp -pthread -sPTHREAD_POOL_SIZE=2 -fno-rtti -fexceptions -O3 -sEXPORTED_FUNCTIONS=_pkpy_delete,_pkpy_new_repl,_pkpy_repl_input,_pkpy_new_tvm,_pkpy_tvm_exec_async,_pkpy_tvm_get_state,_pkpy_tvm_read_jsonrpc_request,_pkpy_tvm_reset_state,_pkpy_tvm_terminate,_pkpy_tvm_write_jsonrpc_response,_pkpy_new_vm,_pkpy_vm_add_module,_pkpy_vm_eval,_pkpy_vm_exec,_pkpy_vm_get_global,_pkpy_vm_read_output -sEXPORTED_RUNTIME_METHODS=ccall -o web/lib/pocketpy.js
\ No newline at end of file
+em++ src/main.cpp ${PTHREAD_FLAG:--pthread -sPTHREAD_POOL_SIZE=2} -fno-rtti -fexceptions -O3 -sEXPORTED_FUNCTIONS=_pkpy_delete,_pkpy_new_repl,_pkpy_repl_input,_pkpy_new_tvm,_pkpy_tvm_exec_async,_pkpy_tvm_get_state,_pkpy_tvm_read_jsonrpc_request,_pkpy_tvm_reset_state,_pkpy_tvm_terminate,_pkpy_tvm_write_jsonrpc_response,_pkpy_new_vm,_pkpy_vm_add_module,_pkpy_vm_eval,_pkpy_vm_exec,_pkpy_vm_get_global,_pkpy_vm_read_output -sEXPORTED_RUNTIME_METHODS=ccall -o web/lib/pocketpy.js
\ No newline at end of file