diff --git a/Makefile b/Makefile
index 3445247..2c97b5d 100644
--- a/Makefile
+++ b/Makefile
@@ -2,22 +2,13 @@ TEST?=./...
 
 default: test
 
-fmt: hcl/y.go json/y.go
+fmt: generate
 	go fmt ./...
 
-test: hcl/y.go json/y.go
+test: generate
 	go test $(TEST) $(TESTARGS)
 
-hcl/y.go: hcl/parse.y
-	cd hcl && \
-		go tool yacc -p "hcl" parse.y
+generate:
+	go generate ./...
 
-json/y.go: json/parse.y
-	cd json/ && \
-		go tool yacc -p "json" parse.y
-
-clean:
-	rm -f hcl/y.go
-	rm -f json/y.go
-
-.PHONY: default test
+.PHONY: default generate test
diff --git a/hcl/lex.go b/hcl/lex.go
index e0c96b1..825b7da 100644
--- a/hcl/lex.go
+++ b/hcl/lex.go
@@ -8,6 +8,8 @@ import (
 	"unicode/utf8"
 )
 
+//go:generate go tool yacc -p "hcl" parse.y
+
 // The parser expects the lexer to return 0 on EOF.
 const lexEOF = 0
 
diff --git a/json/lex.go b/json/lex.go
index 0c1299c..0b07e36 100644
--- a/json/lex.go
+++ b/json/lex.go
@@ -8,6 +8,8 @@ import (
 	"unicode/utf8"
 )
 
+//go:generate go tool yacc -p "json" parse.y
+
 // This marks the end of the lexer
 const lexEOF = 0