diff --git a/.docker/Dockerfile b/.docker/Dockerfile
index b894c62ae3953b96aca1e3a88da795d4c8f13a69..507aa4dcae5e8d777917fccafe65a24533698792 100644
--- a/.docker/Dockerfile
+++ b/.docker/Dockerfile
@@ -1,7 +1,7 @@
-FROM debian:buster-backports
+FROM debian:bullseye
 
 RUN apt-get update
-RUN apt-get install -y cmake/buster-backports
+RUN apt-get install -y cmake
 RUN apt-get install -y lcov
 RUN apt-get install -y doxygen
 RUN apt-get install -y clang-format-11 clang-tidy-11
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 3466d875eaa7adecd42daf71a397802b79c6eb42..12741c41d4e31e12548711f14dc716b4eb7f65c8 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -112,5 +112,8 @@ if (LCOV_PATH)
 else ()
     if (NOT SKIP_CODE_COVERAGE)
         message(WARNING "Could not generate code coverage report. Please install lcov.")
+        add_custom_target(unit_test_coverage ctest -L caosdb-cpplib-unit-tests
+            DEPENDS caosdb ccaosdb ${test_cases}
+        )
     endif()
 endif ()