diff --git a/build/toolchain.emscripten.mak b/build/toolchain.emscripten.mak
index 9676ab7ca..8b7c2f1bb 100644
--- a/build/toolchain.emscripten.mak
+++ b/build/toolchain.emscripten.mak
@@ -70,8 +70,8 @@ _mp_hal_input \
 _mp_import_name \
 _mp_parse_compile_execute
 
-EMTERPRETIFY_WHITELIST = $(foreach sym,$(EMSCRIPTEN_ASYNC_SYMBOLS),"$(sym)",),
-EMFLAGS = -s EMTERPRETIFY=1 -s EMTERPRETIFY_ASYNC=1 -s EMTERPRETIFY_WHITELIST='[$(EMTERPRETIFY_WHITELIST:,,=)]'
+EMTERPRETIFY_WHITELIST = $(foreach sym,$(EMSCRIPTEN_ASYNC_SYMBOLS),"$(sym)",)END
+EMFLAGS = -s EMTERPRETIFY=1 -s EMTERPRETIFY_ASYNC=1 -s EMTERPRETIFY_WHITELIST='[$(EMTERPRETIFY_WHITELIST:,END=)]'
 
 ifeq ($(DEBUG),1)
 EMFLAGS += --profiling-funcs