diff --git a/.build/cassandra-build-deps-template.xml b/.build/cassandra-build-deps-template.xml
index b5db6846da..6c6eb78fd2 100644
--- a/.build/cassandra-build-deps-template.xml
+++ b/.build/cassandra-build-deps-template.xml
@@ -127,5 +127,9 @@
       <groupId>com.github.tomakehurst</groupId>
       <artifactId>wiremock-jre8</artifactId>
     </dependency>
+    <dependency>
+      <groupId>de.jflex</groupId>
+      <artifactId>jflex</artifactId>
+    </dependency>
   </dependencies>
 </project>
diff --git a/.build/cassandra-deps-template.xml b/.build/cassandra-deps-template.xml
index e907bffa82..4041a54195 100644
--- a/.build/cassandra-deps-template.xml
+++ b/.build/cassandra-deps-template.xml
@@ -324,10 +324,6 @@
       <groupId>org.hdrhistogram</groupId>
       <artifactId>HdrHistogram</artifactId>
     </dependency>
-    <dependency>
-      <groupId>de.jflex</groupId>
-      <artifactId>jflex</artifactId>
-    </dependency>
     <dependency>
       <groupId>com.github.rholder</groupId>
       <artifactId>snowball-stemmer</artifactId>
diff --git a/CHANGES.txt b/CHANGES.txt
index caea458186..371026ce58 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -166,6 +166,7 @@ Merged from 4.0:
  * Fix Down nodes counter in nodetool describecluster (CASSANDRA-18512)
  * Remove unnecessary shuffling of GossipDigests in Gossiper#makeRandomGossipDigest (CASSANDRA-18546)
 Merged from 3.11:
+ * Moved jflex from runtime to build dependencies (CASSANDRA-18664)
  * Fix CAST function for float to decimal (CASSANDRA-18647)
  * Suppress CVE-2022-45688 (CASSANDRA-18643)
  * Remove unrepaired SSTables from garbage collection when only_purge_repaired_tombstones is true (CASSANDRA-14204)