diff --git a/.dockerignore b/.dockerignore
index 6415e08b..163278ea 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -12,7 +12,10 @@ ocrd-all-module-dir.json
 opencv-python
 # only needed for testing:
 # (but we may want that, only 169 MB)
-# **/assets/*
+**/assets/*
+# recursive submodules, too deep
+ocrd_tesserocr/repo/tesseract/test/*
+ocrd_tesserocr/repo/tesseract/unittest/third_party/googletest/*
 # avoid interference with host-local builds:
 **/build/*
 */.eggs/*
diff --git a/Dockerfile b/Dockerfile
index c00c2bc4..2fee212a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -112,7 +112,9 @@ RUN echo "make $PARALLEL all" >> docker.sh
 # remove unneeded automatic deps and clear pkg cache
 RUN echo "apt-get -y remove automake autoconf libtool pkg-config g++ && apt-get -y clean" >> docker.sh
 # clean-up some temporary files (git repos are also installation targets and must be kept)
-RUN echo "make -i clean-olena clean-tesseract; rm -fr /.cache" >> docker.sh
+RUN echo "make -i clean-tesseract" >> docker.sh
+RUN echo "make -i clean-olena" >> docker.sh
+RUN echo "rm -fr /.cache" >> docker.sh
 # run the script in one layer/step (to minimise image size)
 # (and export all variables)
 RUN set -a; bash docker.sh