diff --git a/Makefile b/Makefile
index c2c65d5e01..a611539717 100644
--- a/Makefile
+++ b/Makefile
@@ -171,28 +171,28 @@ $(GOPATH)/bin/protoc-gen-swagger:
 
 $(PROTO_SRC)/settings.pb.go: $(PROTO_SRC)/settings.proto
 	protoc \
-		--plugin=protoc-gen-go=$GOPATH/bin/protoc-gen-go \
+		--plugin=protoc-gen-go=$(GOPATH)/bin/protoc-gen-go \
 		-I=third_party/ \
 		-I=$(PROTO_SRC)/ \
 		--go_out=. settings.proto
 
 $(PROTO_SRC)/settings.pb.micro.go: $(PROTO_SRC)/settings.proto
 	protoc \
-		--plugin=protoc-gen-micro=$GOPATH/bin/protoc-gen-micro \
+		--plugin=protoc-gen-micro=$(GOPATH)/bin/protoc-gen-micro \
 		-I=third_party/ \
 		-I=$(PROTO_SRC)/ \
 		--micro_out=. settings.proto
 
 $(PROTO_SRC)/settings.pb.web.go: $(PROTO_SRC)/settings.proto
 	protoc \
-		--plugin=protoc-gen-microweb=$GOPATH/bin/protoc-gen-microweb \
+		--plugin=protoc-gen-microweb=$(GOPATH)/bin/protoc-gen-microweb \
 		-I=third_party/ \
 		-I=$(PROTO_SRC)/ \
 		--microweb_out=. settings.proto
 
 $(PROTO_SRC)/settings.swagger.json: $(PROTO_SRC)/settings.proto
 	protoc \
-		--plugin=protoc-gen-swagger=$GOPATH/bin/protoc-gen-swagger \
+		--plugin=protoc-gen-swagger=$(GOPATH)/bin/protoc-gen-swagger \
 		-I=third_party/ \
 		-I=$(PROTO_SRC)/ \
 		--swagger_out=$(PROTO_SRC) settings.proto