1 files changed, 1 insertions, 0 deletions
diff --git a/rules.mk b/rules.mk
index 2c4acec1..f04f3f46 100644
--- a/rules.mk
+++ b/rules.mk
@@ -18,6 +18,7 @@ $(BUILD)/$(BIN).html: $(OBJS)
 	@echo HTML $@
 	@$(CC) $(LDFLAGS) $(OBJS) $(LIBS) -o $@ \
 		-s ASYNCIFY=1 \
+		-s EXPORTED_RUNTIME_METHODS=lengthBytesUTF8,printErr \
 		-s EXPORTED_FUNCTIONS=_main \
 		--shell-file=$(TOP)/watch-library/simulator/shell.html