diff --git a/Makefile b/Makefile
index 22af928..f95120e 100644
--- a/Makefile
+++ b/Makefile
@@ -113,7 +113,7 @@ endif
 		-t $(docker_repo)/kopano_$(component):builder $(component)/
 
 build-base: ## Build new base image.
-	docker pull debian:stretch
+	docker pull debian:buster
 	component=base make build
 
 build-core:
diff --git a/base/Dockerfile b/base/Dockerfile
index 98d981a..01108cd 100644
--- a/base/Dockerfile
+++ b/base/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:stretch
+FROM debian:buster
 
 ARG VCS_REF
 ARG ADDITIONAL_KOPANO_PACKAGES=""
diff --git a/core/Dockerfile b/core/Dockerfile
index 3ca4da3..473600b 100644
--- a/core/Dockerfile
+++ b/core/Dockerfile
@@ -13,7 +13,7 @@ ARG KOPANO_CORE_VERSION=newest
 ENV \
     ADDITIONAL_KOPANO_PACKAGES=$ADDITIONAL_KOPANO_PACKAGES \
     DOWNLOAD_COMMUNITY_PACKAGES=$DOWNLOAD_COMMUNITY_PACKAGES \
-    DOWNLOAD_DISTRIBUTION="Debian_9.0" \
+    DOWNLOAD_DISTRIBUTION="Debian_10" \
     DOWNLOAD_CHANNEL="community" \
     DOWNLOAD_BRANCH="" \
     KOPANO_CORE_REPOSITORY_URL=$KOPANO_CORE_REPOSITORY_URL \