diff --git a/pom.xml b/pom.xml
index dde26d5..8a1803b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -36,7 +36,7 @@
         <version.javalin>3.13.11</version.javalin>
         <version.jetty>9.4.43.v20210629</version.jetty> <!-- N.B. needs to be synchronised/tested with Javalin version -->
         <version.jsoniter>0.9.23</version.jsoniter>
-        <version.fastutil>8.5.4</version.fastutil>
+        <version.fastutil>8.5.6</version.fastutil>
         <version.javassist>3.28.0-GA</version.javassist>
         <version.okHttp3>4.9.1</version.okHttp3>
         <version.commons-lang3>3.12.0</version.commons-lang3>