make C# docker image in sync with GCE performance workers
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
index c26c9a2..2a59628 100644
--- a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
+++ b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
@@ -99,8 +99,8 @@
# Install dotnet SDK based on https://www.microsoft.com/net/core#debian
RUN apt-get update && apt-get install -y curl libunwind8 gettext
-# dotnet-dev-1.0.0-preview2-003121
-RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=809130
+# dotnet-dev-1.0.0-preview2-003131
+RUN curl -sSL -o dotnet100.tar.gz https://go.microsoft.com/fwlink/?LinkID=827530
RUN mkdir -p /opt/dotnet && tar zxf dotnet100.tar.gz -C /opt/dotnet
# dotnet-dev-1.0.1
RUN curl -sSL -o dotnet101.tar.gz https://go.microsoft.com/fwlink/?LinkID=843453