diff --git a/CHANGES.txt b/CHANGES.txt
index c661db958e..e14e315604 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 4.0.9
+ * Update zstd-jni library to version 1.5.5 (CASSANDRA-18429)
  * Backport CASSANDRA-17205 to 4.0 branch - Remove self-reference in SSTableTidier (CASSANDRA-18332)
  * Avoid loading the preferred IP for BulkLoader streaming (CASSANDRA-18370)
  * Fix BufferPool incorrect memoryInUse when putUnusedPortion is used (CASSANDRA-18311)
diff --git a/build.xml b/build.xml
index 979b116ee7..b270c3f56e 100644
--- a/build.xml
+++ b/build.xml
@@ -512,7 +512,7 @@
           <dependency groupId="org.xerial.snappy" artifactId="snappy-java" version="1.1.2.6"/>
           <dependency groupId="org.lz4" artifactId="lz4-java" version="1.8.0"/>
           <dependency groupId="com.ning" artifactId="compress-lzf" version="0.8.4" scope="provided"/>
-          <dependency groupId="com.github.luben" artifactId="zstd-jni" version="1.5.4-1"/>
+          <dependency groupId="com.github.luben" artifactId="zstd-jni" version="1.5.5-1"/>
           <dependency groupId="com.google.guava" artifactId="guava" version="27.0-jre">
             <exclusion groupId="com.google.code.findbugs" artifactId="jsr305" />
             <exclusion groupId="org.codehaus.mojo" artifactId="animal-sniffer-annotations" />