diff --git a/web-modules/ratpack/pom.xml b/web-modules/ratpack/pom.xml
index 156080ccca..1ef358cc55 100644
--- a/web-modules/ratpack/pom.xml
+++ b/web-modules/ratpack/pom.xml
@@ -85,6 +85,20 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <argLine>
+                        --add-opens java.base/java.lang=ALL-UNNAMED
+                    </argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
     <properties>
         <ratpack.version>1.9.0</ratpack.version>
         <httpclient.version>4.5.3</httpclient.version>