diff --git a/build/docker/ubuntu-bionic/Dockerfile b/build/docker/ubuntu-bionic/Dockerfile
index 43c99a9..db19112 100644
--- a/build/docker/ubuntu-bionic/Dockerfile
+++ b/build/docker/ubuntu-bionic/Dockerfile
@@ -15,7 +15,7 @@
 # Using all stock Ubuntu Bionic packaging except for:
 # - cl: want latest
 # - d: dmd does not come with Ubuntu
-# - dart: does not come with Ubuntu. Pinned to last 1.x release
+# - dart: does not come with Ubuntu - we use 2.x here
 # - dotnet: does not come with Ubuntu
 # - go: want latest
 # - nodejs: want v8, bionic comes with v6
@@ -46,7 +46,6 @@
 RUN curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
     curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > \
       /etc/apt/sources.list.d/dart_stable.list
-ENV DART_VERSION 1.24.3-1
 
 # dotnet (netcore)
 RUN curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > /etc/apt/trusted.gpg.d/microsoft.gpg && \
@@ -118,6 +117,7 @@
     mv deimos-openssl-1.1.0h/C/* /usr/include/dmd/druntime/import/C/ && \
     rm -rf deimos-openssl-1.1.0h
 
+ENV DART_VERSION 2.1.0-1
 RUN apt-get install -y --no-install-recommends \
       `# Dart dependencies` \
       dart=$DART_VERSION
diff --git a/build/docker/ubuntu-xenial/Dockerfile b/build/docker/ubuntu-xenial/Dockerfile
index 3372b4d..88895a0 100644
--- a/build/docker/ubuntu-xenial/Dockerfile
+++ b/build/docker/ubuntu-xenial/Dockerfile
@@ -14,7 +14,7 @@
 # Apache Thrift Docker build environment for Ubuntu Xenial
 # Using all stock Ubuntu Xenial packaging except for:
 # - d: does not come with Ubuntu so we're installing 2.075.1 for coverage
-# - dart: does not come with Ubuntu so we're installing 1.22.1 for coverage
+# - dart: does not come with Ubuntu so we're installing 1.24.3 for coverage
 # - dotnet: does not come with Ubuntu
 # - go: Xenial comes with 1.6, but we need 1.7 or later
 # - nodejs: Xenial comes with 4.2.6 which exits LTS April 2018, so we're installing 6.x
@@ -50,7 +50,6 @@
 RUN curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
     curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > \
       /etc/apt/sources.list.d/dart_stable.list
-ENV DART_VERSION 1.22.1-1
 
 # dotnet (core)
 RUN curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > /etc/apt/trusted.gpg.d/microsoft.gpg && \
@@ -120,6 +119,7 @@
     mv openssl-1.1.6-1.0.1g/C/* /usr/include/dmd/druntime/import/C/ && \
     rm -rf openssl-1.1.6-1.0.1g
 
+ENV DART_VERSION 1.24.3-1
 RUN apt-get install -y --no-install-recommends \
 `# Dart dependencies` \
       dart=$DART_VERSION
@@ -127,7 +127,7 @@
 
 RUN apt-get install -y --no-install-recommends \
 `# dotnet core dependencies` \
-      dotnet-sdk-2.1.4
+      dotnet-sdk-2.1
 
 RUN apt-get install -y --no-install-recommends \
 `# Erlang dependencies` \