diff --git a/Makefile b/Makefile
index d771514..c81f5e0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: test clean
+.PHONY: test bench clean
 
 sentencepiece/sentencepiece_model.pb.go: sentencepiece/sentencepiece_model.proto
 	protoc --go_out=. $<
@@ -10,5 +10,8 @@ cmd/dumpspm/dumpspm: cmd/dumpspm/main.go
 test:
 	go test -cover -coverprofile=c.out ./sentencepiece && go tool cover -html=c.out -o coverage.html
 
+bench:
+	go test -benchmem ./sentencepiece -bench Benchmark.*
+
 clean:
 	rm -f *.out coverage.html cmd/dumpspm/dumpspm
\ No newline at end of file
diff --git a/README.md b/README.md
index 7f1bc77..1499df5 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@ Sentence Piece Encoder
 ======================
 
 This is pure go implementation of the sentencepiece encoder.
-It takes a sentencepiece model and tokenizes it.
+Create an encoder for the given sentencepiece model and then use
+use the `Tokenize` function to split the input text into tokens.
 
 Example: