diff --git a/ci/gitlab-ci.yml b/ci/gitlab-ci.yml
index b14878fc34f8e2eb1ea65194382605be8718b7ad..a1eab5af5080c6d23ee573dffbbfa13456bf6f77 100644
--- a/ci/gitlab-ci.yml
+++ b/ci/gitlab-ci.yml
@@ -82,12 +82,12 @@ before_script:
 build:stretch:
     extends: .build
     variables:
-        BUILD_IMAGE: 'debian:stretch'
+        BUILD_IMAGE: 'debian:stretch-slim'
 
 build:buster:
     extends: .build
     variables:
-        BUILD_IMAGE: 'debian:buster'
+        BUILD_IMAGE: 'debian:buster-slim'
 
 build:bionic:
     extends: .build