diff --git a/annotation/pom.xml b/annotation/pom.xml
index ab12eb88b..276a3e847 100644
--- a/annotation/pom.xml
+++ b/annotation/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>annotation</artifactId>
 	<packaging>jar</packaging>
diff --git a/benchmark/assertj/pom.xml b/benchmark/assertj/pom.xml
index 1e7e9f87f..16d73603e 100644
--- a/benchmark/assertj/pom.xml
+++ b/benchmark/assertj/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>benchmark</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>benchmark.assertj</artifactId>
 	<packaging>jar</packaging>
diff --git a/benchmark/guava/pom.xml b/benchmark/guava/pom.xml
index 5da57f426..ab743fee8 100644
--- a/benchmark/guava/pom.xml
+++ b/benchmark/guava/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>benchmark</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>benchmark.guava</artifactId>
 	<packaging>jar</packaging>
diff --git a/benchmark/java/pom.xml b/benchmark/java/pom.xml
index 5ed0a8e16..6d2964ba0 100644
--- a/benchmark/java/pom.xml
+++ b/benchmark/java/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>benchmark</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>benchmark.java</artifactId>
 	<packaging>jar</packaging>
diff --git a/benchmark/pom.xml b/benchmark/pom.xml
index 32321affe..644339fe6 100644
--- a/benchmark/pom.xml
+++ b/benchmark/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>benchmark</artifactId>
 	<packaging>pom</packaging>
diff --git a/guava/pom.xml b/guava/pom.xml
index a60deb90f..afcccf49a 100644
--- a/guava/pom.xml
+++ b/guava/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>guava</artifactId>
 	<packaging>jar</packaging>
diff --git a/jackson/pom.xml b/jackson/pom.xml
index 535220800..e2669b5c6 100644
--- a/jackson/pom.xml
+++ b/jackson/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>jackson</artifactId>
 	<packaging>jar</packaging>
diff --git a/java/pom.xml b/java/pom.xml
index 6f9971781..7a5392083 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>java</artifactId>
 	<packaging>jar</packaging>
diff --git a/pom.xml b/pom.xml
index c1f8c5c06..48f948bc0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,10 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.github.cowwoc.requirements</groupId>
 	<artifactId>root</artifactId>
-	<version>9.0.0-SNAPSHOT</version>
+	<version>9.0.0</version>
 	<packaging>pom</packaging>
 	<name>Requirements</name>
 	<description>A fluent API for enforcing design contracts with automatic message generation</description>
@@ -22,7 +21,7 @@
 		<url>https://github.com/cowwoc/requirements.java/</url>
 		<connection>scm:git:https://github.com/cowwoc/requirements.java/</connection>
 		<developerConnection>scm:git:https://github.com/cowwoc/requirements.java/</developerConnection>
-		<tag>HEAD</tag>
+		<tag>release-9.0.0</tag>
 	</scm>
 
 	<developers>
diff --git a/test/pom.xml b/test/pom.xml
index f5959569c..382c4380f 100644
--- a/test/pom.xml
+++ b/test/pom.xml
@@ -1,17 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.github.cowwoc.requirements</groupId>
 		<artifactId>root</artifactId>
-		<version>9.0.0-SNAPSHOT</version>
+		<version>9.0.0</version>
 	</parent>
 	<artifactId>test</artifactId>
 	<packaging>jar</packaging>
 
 	<properties>
-		<argLine/>
+		<argLine />
 	</properties>
 	<dependencies>
 		<dependency>
@@ -51,7 +50,7 @@
 		<dependency>
 			<groupId>com.github.cowwoc.requirements</groupId>
 			<artifactId>jackson</artifactId>
-			<version>9.0.0-SNAPSHOT</version>
+			<version>9.0.0</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>