diff --git a/src/Dockerfile.arch b/src/Dockerfile.arch
index b5fd7c0..d014651 100644
--- a/src/Dockerfile.arch
+++ b/src/Dockerfile.arch
@@ -2,6 +2,7 @@ FROM base/archlinux:2014.07.03
 MAINTAINER Junegunn Choi <junegunn.c@gmail.com>
 
 # apt-get
+RUN pacman-key --populate archlinux && pacman-key --refresh-keys
 RUN pacman-db-upgrade && pacman -Syu --noconfirm base-devel git
 
 # Install Go 1.4
diff --git a/src/Makefile b/src/Makefile
index 33c23ab..3304f57 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -75,7 +75,7 @@ docker-arch:
 	docker build -t junegunn/arch-sandbox - < Dockerfile.arch
 
 docker-ubuntu:
-	docker build -t junegunn/arch-sandbox - < Dockerfile.ubuntu
+	docker build -t junegunn/ubuntu-sandbox - < Dockerfile.ubuntu
 
 arch: docker-arch
 	docker run -i -t -v $(GOPATH):/go junegunn/$@-sandbox \