diff --git a/Dockerfile b/Dockerfile
index dd045e7..af09e01 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,12 +9,17 @@ ENV SBT_HOME=/usr/local/sbt
 ENV PATH=${SBT_HOME}/bin:${PATH}
 
 # Install required tools and the specific version of SBT
+# The .tgz for 0.13.11 is missing from GitHub releases. We'll install it manually.
 RUN apt-get update && \
     apt-get install -y curl && \
-    curl -L -o sbt.tgz https://github.com/sbt/sbt/releases/download/v${SBT_VERSION}/sbt-${SBT_VERSION}.tgz && \
-    tar -xzf sbt.tgz -C /usr/local && \
-    rm sbt.tgz && \
-    apt-get purge -y --auto-remove curl
+    mkdir -p "${SBT_HOME}/bin" && \
+    curl -L -o "${SBT_HOME}/bin/sbt-launch.jar" "https://repo1.maven.org/maven2/org/scala-sbt/sbt-launch/${SBT_VERSION}/sbt-launch-${SBT_VERSION}.jar" && \
+    echo '#!/bin/sh' > "${SBT_HOME}/bin/sbt" && \
+    echo 'SBT_OPTS="-Xms512M -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M"' >> "${SBT_HOME}/bin/sbt" && \
+    echo 'java $SBT_OPTS -jar `dirname $0`/sbt-launch.jar "$@"' >> "${SBT_HOME}/bin/sbt" && \
+    chmod 0755 "${SBT_HOME}/bin/sbt" && \
+    apt-get purge -y --auto-remove curl && \
+    rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app