diff --git a/README.in b/README.in
index 2cfa7a0..51b30a2 100644
--- a/README.in
+++ b/README.in
@@ -7,7 +7,7 @@ A specification for structured, user-facing error message values.
 
   * Simple interfaces for exposing error information in a structured manner.
   * Convenient builders for structured error values.
-  * Written in pure Java 21.
+  * Written in pure Java 17.
   * [OSGi](https://www.osgi.org/) ready.
   * [JPMS](https://en.wikipedia.org/wiki/Java_Platform_Module_System) ready.
   * ISC license.
diff --git a/README.md b/README.md
index 1a04765..f28b166 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ seltzer
 [![Maven Central](https://img.shields.io/maven-central/v/com.io7m.seltzer/com.io7m.seltzer.svg?style=flat-square)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.io7m.seltzer%22)
 [![Maven Central (snapshot)](https://img.shields.io/nexus/s/com.io7m.seltzer/com.io7m.seltzer?server=https%3A%2F%2Fs01.oss.sonatype.org&style=flat-square)](https://s01.oss.sonatype.org/content/repositories/snapshots/com/io7m/seltzer/)
 [![Codecov](https://img.shields.io/codecov/c/github/io7m-com/seltzer.svg?style=flat-square)](https://codecov.io/gh/io7m-com/seltzer)
-![Java Version](https://img.shields.io/badge/21-java?label=java&color=e6c35c)
+![Java Version](https://img.shields.io/badge/17-java?label=java&color=e65cc3)
 
 ![com.io7m.seltzer](./src/site/resources/seltzer.jpg?raw=true)
 
@@ -23,7 +23,7 @@ A specification for structured, user-facing error message values.
 
   * Simple interfaces for exposing error information in a structured manner.
   * Convenient builders for structured error values.
-  * Written in pure Java 21.
+  * Written in pure Java 17.
   * [OSGi](https://www.osgi.org/) ready.
   * [JPMS](https://en.wikipedia.org/wiki/Java_Platform_Module_System) ready.
   * ISC license.
diff --git a/pom.xml b/pom.xml
index 02e14d0..09e6f56 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,9 +26,14 @@
   </modules>
 
   <properties>
-    <com.io7m.xstructural.version>1.8.0</com.io7m.xstructural.version>
+    <!-- Configuration. -->
     <io7m.api.previousVersion>1.0.0</io7m.api.previousVersion>
-    <io7m.java.targetJavaVersion>21</io7m.java.targetJavaVersion>
+    <io7m.java.targetJavaVersion>17</io7m.java.targetJavaVersion>
+
+    <!-- io7m dependencies. -->
+    <com.io7m.xstructural.version>1.8.0</com.io7m.xstructural.version>
+
+    <!-- Third-party dependencies. -->
     <junit.version>5.10.2</junit.version>
     <jqwik.version>1.8.4</jqwik.version>
   </properties>