diff --git a/pom.xml b/pom.xml
index 288b6044..2b6543e9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -39,7 +39,7 @@
     <io7m.java.targetJavaVersion>17</io7m.java.targetJavaVersion>
 
     <!-- io7m dependencies. -->
-    <com.io7m.xstructural.version>1.8.1</com.io7m.xstructural.version>
+    <com.io7m.xstructural.version>1.9.0</com.io7m.xstructural.version>
 
     <!-- Third-party dependencies. -->
     <io7m.org.immutables.version>2.10.1</io7m.org.immutables.version>