diff --git a/Dockerfile b/Dockerfile
index c012c5a..872683e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,6 +13,7 @@ RUN apt-get update && \
                     make \
                     git \
                     bc \
+                    bzip2 \
                     bison \
                     flex \
                     python-dev \
diff --git a/build-boot-rpi b/build-boot-rpi
index 5e03f5c..1a803d7 100755
--- a/build-boot-rpi
+++ b/build-boot-rpi
@@ -12,7 +12,7 @@ TMP=$(mktemp -d tmp.XXXXXX)
 cd "${TMP}"
 
 build-image tmp.img
-build-u_boot u-boot "${DEFCONFIG}" "${TUPLE}"
+build-u_boot "${DEFCONFIG}" "${TUPLE}"
 
 # Write Raspberry Pi boot config
 cat << EOF > config.txt
diff --git a/build-boot-sunxi b/build-boot-sunxi
index 2f07682..25072f3 100755
--- a/build-boot-sunxi
+++ b/build-boot-sunxi
@@ -12,7 +12,7 @@ TMP=$(mktemp -d tmp.XXXXXX)
 cd "${TMP}"
 
 build-image tmp.img
-build-u_boot u-boot "${DEFCONFIG}" "${TUPLE}"
+build-u_boot "${DEFCONFIG}" "${TUPLE}"
 
 # Copy U-Boot to 8192 bytes from start
 dd if=u-boot/u-boot-sunxi-with-spl.bin of=tmp.img bs=1K seek=8
diff --git a/build-u_boot b/build-u_boot
index 561895a..2bd0516 100755
--- a/build-u_boot
+++ b/build-u_boot
@@ -1,27 +1,42 @@
 #!/bin/sh
 # Download and build latest version of U-Boot
 
-UBOOTDIR="${1}" # For example "u-boot"
-DEFCONFIG="${2}" # For example "rpi_3_defconfig"
-TUPLE="${3}" # For example "aarch64-linux-gnu"
+DEFCONFIG="${1}" # For example "rpi_3_defconfig"
+TUPLE="${2}" # For example "aarch64-linux-gnu"
+
+TARBALL="${U_BOOT_TARBALL}"
+GIT_REV="${U_BOOT_GIT_REV}"
+GIT_URL="${U_BOOT_GIT_URL:-git://git.denx.de/u-boot.git}"
 
 set -e
 
-# U-Boot version to build
-VERSION=$(git ls-remote --tags --refs "git://git.denx.de/u-boot.git" "v????.??" | \
-          cut -f 2 | \
-          grep -o "v....\..." | \
-          tail -n 1)
+if [ ! -s "${TARBALL}" ]
+then
+	if [ -z "${GIT_REV}" ]
+	then
+		# U-Boot version to build
+		GIT_REV=$(git ls-remote --tags \
+		                        --refs \
+		                        "${GIT_URL}" \
+		                        "v????.??" | \
+		          cut -f 2 | \
+		          grep -o "v....\..." | \
+		          tail -n 1)
+	fi
 
-# Download U-Boot
-git clone --branch "$VERSION" \
-          --depth 1 \
-          --reference-if-able "/mnt/git-cache/u-boot.git" \
-          --dissociate \
-          "git://git.denx.de/u-boot.git" "${UBOOTDIR}"
+	# Download U-Boot
+	git clone --branch "${GIT_REV}" \
+	          --depth 1 \
+	          "${GIT_URL}" u-boot
+else
+	# Extract U-Boot
+	tar -xf "${TARBALL}"
+
+	mv u-boot-????.?? u-boot
+fi
 
 # Step into U-Boot directory
-cd "${UBOOTDIR}"
+cd u-boot
 
 # Setup ARCH
 case "${TUPLE}" in
diff --git a/dockerfiles/Dockerfile.arm32v7 b/dockerfiles/Dockerfile.arm32v7
index e5faa8b..be5ff88 100644
--- a/dockerfiles/Dockerfile.arm32v7
+++ b/dockerfiles/Dockerfile.arm32v7
@@ -12,6 +12,7 @@ RUN apt-get update && \
                     make \
                     git \
                     bc \
+                    bzip2 \
                     bison \
                     flex \
                     python-dev \
diff --git a/dockerfiles/Dockerfile.arm32v7-on-amd64 b/dockerfiles/Dockerfile.arm32v7-on-amd64
index b5f8e0d..319f12f 100644
--- a/dockerfiles/Dockerfile.arm32v7-on-amd64
+++ b/dockerfiles/Dockerfile.arm32v7-on-amd64
@@ -22,6 +22,7 @@ RUN apt-get update && \
                     make \
                     git \
                     bc \
+                    bzip2 \
                     bison \
                     flex \
                     python-dev \
diff --git a/dockerfiles/Dockerfile.arm64v8 b/dockerfiles/Dockerfile.arm64v8
index 08ef450..776e90a 100644
--- a/dockerfiles/Dockerfile.arm64v8
+++ b/dockerfiles/Dockerfile.arm64v8
@@ -12,6 +12,7 @@ RUN apt-get update && \
                     make \
                     git \
                     bc \
+                    bzip2 \
                     bison \
                     flex \
                     python-dev \
diff --git a/dockerfiles/Dockerfile.arm64v8-on-amd64 b/dockerfiles/Dockerfile.arm64v8-on-amd64
index cc458ae..80413e2 100644
--- a/dockerfiles/Dockerfile.arm64v8-on-amd64
+++ b/dockerfiles/Dockerfile.arm64v8-on-amd64
@@ -22,6 +22,7 @@ RUN apt-get update && \
                     make \
                     git \
                     bc \
+                    bzip2 \
                     bison \
                     flex \
                     python-dev \
diff --git a/rebuild-boots b/rebuild-boots
index dcace71..3c5281b 100755
--- a/rebuild-boots
+++ b/rebuild-boots
@@ -2,19 +2,20 @@
 # Rebuilds boot images
 
 ARTIFACTS_DIR=${DEBIMG_ARTIFACTS_DIR:-/tmp/debimg/artifacts}
-GIT_CACHE_DIR=${DEBIMG_GIT_CACHE_DIR:-/tmp/debimg/git-cache}
+CACHE_DIR=${DEBIMG_CACHE_DIR:-/tmp/debimg/cache}
 
 docker build -t debimg .
 
 mkdir -p /tmp/debimg/artifacts || exit
-mkdir -p /tmp/debimg/git-cache || exit
+mkdir -p /tmp/debimg/cache || exit
 
 IFS=,
 grep -vE "^#|^\s*$" boards.csv | while read BOARD_ID MODEL MAKE CHIP DEFCONFIG TUPLE TYPE DTB _
 do
     docker run --rm \
                -v "${ARTIFACTS_DIR}":/artifacts \
-               -v "${GIT_CACHE_DIR}":/mnt/git-cache \
+               -v "${CACHE_DIR}":/mnt/cache:ro \
+               -e U_BOOT_TARBALL=/mnt/cache/u-boot-latest.tar.bz2 \
                debimg \
                build-boot-"${TYPE}" /artifacts/boot-"${BOARD_ID}" "${DEFCONFIG}" "${TUPLE}"
 done