diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 06e51c3f4a300e11d8c656c41190dcc87e97a83e..20c3ddef4062438bb45f62fc3abb25aaeb33a14d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -18,8 +18,8 @@ before_script:
     - make -C ${CI_JOB_NAME}
     - '[ "$CI_COMMIT_REF_NAME" != master ] || make -C ${CI_JOB_NAME} push'
 
-'15.3':
+'15.4':
   <<: *build_job
 
-'15.2':
+'15.3':
   <<: *build_job
diff --git a/15.2/Dockerfile b/15.4/Dockerfile
similarity index 83%
rename from 15.2/Dockerfile
rename to 15.4/Dockerfile
index 7e1ae0a0ffca59db2d145e189b0e98af508d7e03..d24690d5125c067e8f010f522771b3b4556b93e8 100644
--- a/15.2/Dockerfile
+++ b/15.4/Dockerfile
@@ -1,4 +1,4 @@
-FROM opensuse/leap:15.2
+FROM opensuse/leap:15.4
 
 RUN zypper refresh -f \
  && zypper update -y \
@@ -13,9 +13,8 @@ RUN zypper --non-interactive install --no-recommends \
   cmake libopenssl-devel ccache \
  && zypper clean
 
-RUN OBS_DIST=openSUSE_Leap_15.2 \
- && zypper --non-interactive addrepo https://download.opensuse.org/repositories/home:/icinga/"${OBS_DIST}"/home:icinga.repo \
- && zypper --gpg-auto-import-keys --non-interactive install spectool createrepo \
+RUN zypper --non-interactive addrepo https://download.opensuse.org/repositories/home:/icinga/15.4/home:icinga.repo \
+ && zypper --gpg-auto-import-keys --non-interactive install spectool createrepo_c \
  && zypper clean -a
 
 RUN rpm --import https://packages.icinga.com/icinga.key \
diff --git a/15.2/Makefile b/15.4/Makefile
similarity index 100%
rename from 15.2/Makefile
rename to 15.4/Makefile
diff --git a/Makefile b/Makefile
index 0c0f4dd47b03bee2e6adeb825cffcb17f362e2e3..d5c60e4c88e4994f34971e83268f233612427036 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,12 @@
-all:
-	$(MAKE) -C 15.2
-	$(MAKE) -C 15.3
+TARGETS := $(patsubst %/Dockerfile,%,$(wildcard */Dockerfile))
+PUSH_TARGETS := $(patsubst %,%-push,$(TARGETS))
 
-push:
-	$(MAKE) -C 15.2 push
-	$(MAKE) -C 15.3 push
+.PHONY: $(TARGETS)
+
+all: $(TARGETS)
+
+$(TARGETS):
+	$(MAKE) -C $@
+
+$(PUSH_TARGETS):
+	$(MAKE) -C $@ push