diff --git a/build/docker/README.md b/build/docker/README.md
index 08023a7..ff0fb0b 100644
--- a/build/docker/README.md
+++ b/build/docker/README.md
@@ -184,7 +184,7 @@
 | java      | 1.8.0_191     | 11.0.3        |       |
 | js        | Node.js 6.17.1, V8 5.1.281.111, npm 3.10.10 | Node.js 10.18.0, V8 6.8.275.32, npm 6.13.4 |     |
 | lua       |               | 5.2.4         | Lua 5.3: see THRIFT-4386 |
-| netstd    | 3.1           | 3.1           | LTS version |
+| netstd    | 5.0           | 5.0           |       |
 | nodejs    | 6.16.0        | 10.16.0       |       |
 | ocaml     |               | 4.05.0        | THRIFT-4517: ocaml 4.02.3 on xenial appears broken |
 | perl      | 5.22.1        | 5.26.1        |       |
diff --git a/build/docker/old/debian-stretch/Dockerfile b/build/docker/old/debian-stretch/Dockerfile
index 48db7e1..06a34cf 100644
--- a/build/docker/old/debian-stretch/Dockerfile
+++ b/build/docker/old/debian-stretch/Dockerfile
@@ -102,7 +102,7 @@
 # project isn't ready for this quite yet:
 # RUN apt-get install -y --no-install-recommends \
 # `# dotnet core dependencies` \
-#       dotnet-sdk-2.0.0
+#       dotnet-sdk-5.0
 
 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 813ef06..854f87c 100644
--- a/build/docker/old/ubuntu-artful/Dockerfile
+++ b/build/docker/old/ubuntu-artful/Dockerfile
@@ -120,7 +120,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-2.1.4
+      dotnet-sdk-5.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \
diff --git a/build/docker/ubuntu-bionic/Dockerfile b/build/docker/ubuntu-bionic/Dockerfile
index c8ecd8e..8487114 100644
--- a/build/docker/ubuntu-bionic/Dockerfile
+++ b/build/docker/ubuntu-bionic/Dockerfile
@@ -126,7 +126,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-3.1
+      dotnet-sdk-5.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \
diff --git a/build/docker/ubuntu-disco/Dockerfile b/build/docker/ubuntu-disco/Dockerfile
index 531718c..a3c0b8e 100644
--- a/build/docker/ubuntu-disco/Dockerfile
+++ b/build/docker/ubuntu-disco/Dockerfile
@@ -126,7 +126,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-3.1
+      dotnet-sdk-5.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \
diff --git a/build/docker/ubuntu-xenial/Dockerfile b/build/docker/ubuntu-xenial/Dockerfile
index e554c53..20ee117 100644
--- a/build/docker/ubuntu-xenial/Dockerfile
+++ b/build/docker/ubuntu-xenial/Dockerfile
@@ -122,7 +122,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-3.1
+      dotnet-sdk-5.0
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \