diff --git a/Makefile b/Makefile
index 82d368c0..fb712969 100644
--- a/Makefile
+++ b/Makefile
@@ -143,7 +143,8 @@ test_go:
 
 EMCC_OPT=-I./include -I./src -I../mcl/include -I./ -Wall -Wextra
 EMCC_OPT+=-O3 -DNDEBUG
-EMCC_OPT+=-s WASM=1 -s NO_EXIT_RUNTIME=1 -s NODEJS_CATCH_EXIT=0 -s NODEJS_CATCH_REJECTION=0  -s MODULARIZE=1 #-s ASSERTIONS=1
+EMCC_OPT+=-s WASM=1 -s NO_EXIT_RUNTIME=1 -s NODEJS_CATCH_EXIT=0 -s NODEJS_CATCH_REJECTION=0 #-s ASSERTIONS=1
+EMCC_OPT+=-s MODULARIZE=1 -s EXPORT_ES6=1 -s USE_ES6_IMPORT_META=0
 EMCC_OPT+=-DCYBOZU_MINIMUM_EXCEPTION
 EMCC_OPT+=-s ABORTING_MALLOC=0
 JS_DEP=src/bls_c384.cpp ../mcl/src/fp.cpp Makefile