diff --git a/tests/docker/Makefile.include b/tests/docker/Makefile.include
index 1d5a6f1fb4..a3174346da 100644
--- a/tests/docker/Makefile.include
+++ b/tests/docker/Makefile.include
@@ -127,10 +127,6 @@ docker-image-debian-nios2-cross: $(DOCKER_FILES_DIR)/debian-toolchain.docker \
     $(DOCKER_FILES_DIR)/debian-nios2-cross.d/build-toolchain.sh
 	$(call debian-toolchain, $@)
 
-# Specialist build images, sometimes very limited tools
-docker-image-debian-microblaze-cross: docker-image-debian10
-docker-image-debian-nios2-cross: docker-image-debian10
-
 # These images may be good enough for building tests but not for test builds
 DOCKER_PARTIAL_IMAGES += debian-alpha-cross
 DOCKER_PARTIAL_IMAGES += debian-powerpc-test-cross
diff --git a/tests/docker/dockerfiles/debian-toolchain.docker b/tests/docker/dockerfiles/debian-toolchain.docker
index 738d808aa6..d3d4d3344e 100644
--- a/tests/docker/dockerfiles/debian-toolchain.docker
+++ b/tests/docker/dockerfiles/debian-toolchain.docker
@@ -4,7 +4,7 @@
 # This dockerfile is used for building a cross-compiler toolchain.
 # The script for building the toolchain is supplied via extra-files.
 #
-FROM qemu/debian10
+FROM docker.io/library/debian:11-slim
 
 # Install build utilities for building gcc and glibc.
 # ??? The build-dep isn't working, missing a number of
@@ -15,6 +15,7 @@ RUN apt update && \
     DEBIAN_FRONTEND=noninteractive eatmydata \
     apt install -y --no-install-recommends \
         bison \
+        ca-certificates \
         flex \
         gawk \
         libmpc-dev \
@@ -32,5 +33,5 @@ RUN cd /root && ./build-toolchain.sh
 # Throw away the extra toolchain build deps, the downloaded source,
 # and the build trees by restoring the original debian10 image,
 # then copying the built toolchain from stage 0.
-FROM qemu/debian10
+FROM docker.io/library/debian:bullseye-slim
 COPY --from=0 /usr/local /usr/local