diff --git a/build/docker/old/debian-stretch/Dockerfile b/build/docker/old/debian-stretch/Dockerfile
index 541223c..628b626 100644
--- a/build/docker/old/debian-stretch/Dockerfile
+++ b/build/docker/old/debian-stretch/Dockerfile
@@ -102,10 +102,10 @@
 # project isn't ready for this quite yet:
 # RUN apt-get install -y --no-install-recommends \
 # `# dotnet core dependencies` \
-#       dotnet-sdk-5.0 \
-#       dotnet-runtime-5.0 \
-#       aspnetcore-runtime-5.0 \
-#       dotnet-apphost-pack-5.0
+#       dotnet-sdk-6.0 \
+#       dotnet-runtime-6.0 \
+#       aspnetcore-runtime-6.0 \
+#       dotnet-apphost-pack-6.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \
diff --git a/build/docker/old/ubuntu-artful/Dockerfile b/build/docker/old/ubuntu-artful/Dockerfile
index 282429a..8068265 100644
--- a/build/docker/old/ubuntu-artful/Dockerfile
+++ b/build/docker/old/ubuntu-artful/Dockerfile
@@ -120,10 +120,10 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-5.0 \
-      dotnet-runtime-5.0 \
-      aspnetcore-runtime-5.0 \
-      dotnet-apphost-pack-5.0
+      dotnet-sdk-6.0 \
+      dotnet-runtime-6.0 \
+      aspnetcore-runtime-6.0 \
+      dotnet-apphost-pack-6.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \