diff --git a/ci/Dockerfile-build.deb b/ci/Dockerfile-build.deb
index a9d0fed47..09ed717f8 100644
--- a/ci/Dockerfile-build.deb
+++ b/ci/Dockerfile-build.deb
@@ -4,6 +4,7 @@ WORKDIR /work/build
 COPY . .
 RUN pwd
 RUN ls -la .
+RUN make clean
 RUN make debian
 RUN ls -ls /work