diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index 93190b1e2a..b6c0405950 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -104,11 +104,11 @@ docker-image-debian-hppa-cross: docker-image-debian10
 docker-image-debian-m68k-cross: docker-image-debian10
 docker-image-debian-mips64-cross: docker-image-debian10
 docker-image-debian-powerpc-cross: docker-image-debian10
+docker-image-debian-ppc64-cross: docker-image-debian10
 docker-image-debian-riscv64-cross: docker-image-debian10
 docker-image-debian-sh4-cross: docker-image-debian10
 docker-image-debian-sparc64-cross: docker-image-debian10
 
-docker-image-debian-ppc64-cross: docker-image-debian-sid
 docker-image-travis: NOUSER=1
 
 # Specialist build images, sometimes very limited tools
@@ -117,7 +117,7 @@ docker-image-tricore-cross: docker-image-debian9
 # These images may be good enough for building tests but not for test builds
 DOCKER_PARTIAL_IMAGES += debian-alpha-cross debian-hppa-cross debian-m68k-cross debian-sh4-cross
 DOCKER_PARTIAL_IMAGES += debian-sparc64-cross debian-mips64-cross debian-riscv64-cross
-DOCKER_PARTIAL_IMAGES += debian-tricore-cross debian-powerpc-cross fedora-i386-cross
+DOCKER_PARTIAL_IMAGES += debian-tricore-cross debian-powerpc-cross debian-ppc64-cross fedora-i386-cross
 DOCKER_PARTIAL_IMAGES += fedora-cris-cross
 
 # Rules for building linux-user powered images
diff --git a/tests/docker/dockerfiles/debian-ppc64-cross.docker b/tests/docker/dockerfiles/debian-ppc64-cross.docker
index e5757fe46e..4bf88ab02d 100644
--- a/tests/docker/dockerfiles/debian-ppc64-cross.docker
+++ b/tests/docker/dockerfiles/debian-ppc64-cross.docker
@@ -1,12 +1,11 @@
 #
 # Docker ppc64 cross-compiler target
 #
-# This docker target builds on the debian sid base image which
-# contains cross compilers for Debian "ports" targets.
-FROM qemu:debian-sid
+# This docker target builds on the debian Buster base image.
+FROM qemu:debian10
 
 RUN apt update && \
     DEBIAN_FRONTEND=noninteractive eatmydata \
     apt install -y --no-install-recommends \
        gcc-powerpc64-linux-gnu \
-       libc6-dev-ppc64-cross || { echo "Failed to build - see debian-sid.docker notes"; exit 1; }
+       libc6-dev-ppc64-cross