diff --git a/impls/purs/Makefile b/impls/purs/Makefile
index 5de690be1b..469536ac63 100644
--- a/impls/purs/Makefile
+++ b/impls/purs/Makefile
@@ -9,7 +9,7 @@ OTHER_SRCS = src/Readline.js src/Readline.purs src/Types.purs src/Reader.purs \
 all: $(BINS)
 
 $(BINS): %.js: src/%.purs $(OTHER_SRCS) node_modules/readline-sync
-	spago bundle-app --main $($(<:src/%=%)) --to $@
+	spago bundle-app --platform=node --main $($(<:src/%=%)) --to $@
 
 
 node_modules/readline-sync:
@@ -32,4 +32,4 @@ stepA_mal.purs = Mal.StepA
 
 
 clean:
-	rm -rf step*.js output/*
\ No newline at end of file
+	rm -rf step*.js output/*