diff --git a/build-image-src/Dockerfile-ruby33 b/build-image-src/Dockerfile-ruby33
index d0d3deb..6619769 100644
--- a/build-image-src/Dockerfile-ruby33
+++ b/build-image-src/Dockerfile-ruby33
@@ -31,8 +31,10 @@ RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-$AWS_CLI_ARCH.zip" -o "a
 ARG SAM_CLI_VERSION
 # need to redefine since ARG is not available after FROM tag: https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact
 ARG IMAGE_ARCH
-RUN curl -L "https://github.com/aws/aws-sam-cli/releases/download/v$SAM_CLI_VERSION/aws-sam-cli-linux-$IMAGE_ARCH.zip" -o "samcli.zip" && \
+# RUN curl -L "https://github.com/aws/aws-sam-cli/releases/download/v$SAM_CLI_VERSION/aws-sam-cli-linux-$IMAGE_ARCH.zip" -o "samcli.zip" && \
+RUN curl -L "https://github.com/aws/aws-sam-cli/releases/download/sam-cli-nightly/aws-sam-cli-linux-$IMAGE_ARCH.zip" -o "samcli.zip" && \
   unzip samcli.zip -d sam-installation && ./sam-installation/install && \
+  rm /usr/local/bin/sam && ln -s /usr/local/bin/sam-nightly /usr/local/bin/sam && \
   rm samcli.zip && rm -rf sam-installation && sam --version
 
 # Prepare virtualenv for lambda builders