diff --git a/jetty/src/main/jetty-base/webapps/nomulus.xml b/jetty/src/main/jetty-base/webapps/nomulus.xml
index b03979805..9e9d1c70b 100644
--- a/jetty/src/main/jetty-base/webapps/nomulus.xml
+++ b/jetty/src/main/jetty-base/webapps/nomulus.xml
@@ -4,4 +4,8 @@
 <Configure id="wac" class="org.eclipse.jetty.ee10.webapp.WebAppContext">
   <Set name="contextPath">/</Set>
   <Set name="war">./webapps/nomulus.war</Set>
+  <Call class="java.lang.System" name="setProperty">
+    <Arg>google.registry.jetty</Arg>
+    <Arg>true</Arg>
+  </Call>
 </Configure>
diff --git a/util/src/main/java/google/registry/util/RegistryEnvironment.java b/util/src/main/java/google/registry/util/RegistryEnvironment.java
index 8b606d3fe..559228080 100644
--- a/util/src/main/java/google/registry/util/RegistryEnvironment.java
+++ b/util/src/main/java/google/registry/util/RegistryEnvironment.java
@@ -47,6 +47,18 @@ public enum RegistryEnvironment {
    */
   UNITTEST;
 
+  /** System property for configuring which environment we should use. */
+  private static final String PROPERTY = "google.registry.environment";
+
+  /**
+   * System property for if Nomulus is running on top of a self-hosted Jetty server (i.e., not in
+   * App Engine).
+   */
+  private static final String JETTY_PROPERTY = "google.registry.jetty";
+
+  private static final boolean ON_JETTY =
+      Boolean.parseBoolean(System.getProperty(JETTY_PROPERTY, "false"));
+
   /** Sets this enum as the name of the registry environment. */
   public RegistryEnvironment setup() {
     return setup(SystemPropertySetter.PRODUCTION_IMPL);
@@ -66,6 +78,7 @@ public enum RegistryEnvironment {
     return valueOf(Ascii.toUpperCase(System.getProperty(PROPERTY, UNITTEST.name())));
   }
 
-  /** System property for configuring which environment we should use. */
-  private static final String PROPERTY = "google.registry.environment";
+  public static boolean isOnJetty() {
+    return ON_JETTY;
+  }
 }