diff --git a/README.md b/README.md
index ca2535e..a91ab53 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ These two images are the concatenated to a single image, which is then written t
 
 To build a boot image for Raspberry Pi 3 B:
 
-    docker build -t sd-images https://github.com/johang/sd-card-images.git sd-images
+    docker build -t sd-images https://github.com/johang/sd-card-images.git
     mkdir -p /tmp/sd-images
     docker run --rm -v /tmp/sd-images:/artifacts sd-images build-boot raspberrypi_3b bcm2837 rpi_3_defconfig aarch64-linux-gnu
 
@@ -32,7 +32,7 @@ The image will end up in /tmp/sd-images on the host.
 
 To build a Debian ext4 root filesystem image for arm64:
 
-    docker build -t sd-images https://github.com/johang/sd-card-images.git sd-images
+    docker build -t sd-images https://github.com/johang/sd-card-images.git
     mkdir -p /tmp/sd-images
     docker run --rm -v /tmp/sd-images:/artifacts sd-images build-debian debian arm64 buster