diff --git a/Dockerfile b/Dockerfile
index 822141da..af504886 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,5 +8,5 @@ VOLUME /commafeed/data
 COPY commafeed-server/config.yml.example config.yml
 COPY commafeed-server/target/commafeed.jar .
 
-ENV JAVA_TOOL_OPTIONS -Djava.net.preferIPv4Stack=true -Xms20m -XX:+UseG1GC -XX:-ShrinkHeapInSteps -XX:G1PeriodicGCInterval=10000 -XX:-G1PeriodicGCInvokesConcurrent -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=10
+ENV JAVA_TOOL_OPTIONS -Djava.net.preferIPv4Stack=true -Xms20m -XX:+UseG1GC -XX:+UseStringDeduplication -XX:-ShrinkHeapInSteps -XX:G1PeriodicGCInterval=10000 -XX:-G1PeriodicGCInvokesConcurrent -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=10
 CMD ["java", "-jar", "commafeed.jar", "server", "config.yml"]
diff --git a/README.md b/README.md
index 5b2c4722..6037d219 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ For example, to limit the JVM to 256MB of memory, use `-Xmx256m`.
 
 The JVM can be configured to release unused memory to the operating system with the following parameters:
 
-    -Xms20m -XX:+UseG1GC -XX:-ShrinkHeapInSteps -XX:G1PeriodicGCInterval=10000 -XX:-G1PeriodicGCInvokesConcurrent -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=10
+    -Xms20m -XX:+UseG1GC -XX:+UseStringDeduplication -XX:-ShrinkHeapInSteps -XX:G1PeriodicGCInterval=10000 -XX:-G1PeriodicGCInvokesConcurrent -XX:MinHeapFreeRatio=5 -XX:MaxHeapFreeRatio=10
 
 This is how the Docker image is configured.
 See [here](https://docs.oracle.com/en/java/javase/17/gctuning/garbage-first-g1-garbage-collector1.html)