diff --git a/core/pom.xml b/core/pom.xml
index dba052a8..e5d6ae35 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -80,6 +80,9 @@
           <includes>
             <include>com/threerings/**/*Test.java</include>
           </includes>
+          <systemPropertyVariables>
+            <java.awt.headless>true</java.awt.headless>
+          </systemPropertyVariables>
         </configuration>
       </plugin>
     </plugins>