diff --git a/start-site/src/main/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizer.java b/start-site/src/main/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizer.java
index a199ce069c8..12937c1a84d 100644
--- a/start-site/src/main/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizer.java
+++ b/start-site/src/main/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizer.java
@@ -31,7 +31,7 @@
 class ObservabilityActuatorBuildCustomizer implements BuildCustomizer<Build> {
 
 	private static final List<String> STANDARD_REGISTRY_IDS = Arrays.asList("datadog", "distributed-tracing",
-			"dynatrace", "graphite", "influx", "new-relic", "otlp-metrics", "wavefront", "zipkin");
+			"dynatrace", "graphite", "influx", "new-relic", "otlp-metrics", "prometheus", "wavefront", "zipkin");
 
 	@Override
 	public void customize(Build build) {
diff --git a/start-site/src/test/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizerTests.java b/start-site/src/test/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizerTests.java
index ed0002ca4b6..6c3f6c9febe 100644
--- a/start-site/src/test/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizerTests.java
+++ b/start-site/src/test/java/io/spring/start/site/extension/dependency/observability/ObservabilityActuatorBuildCustomizerTests.java
@@ -34,7 +34,7 @@ class ObservabilityActuatorBuildCustomizerTests extends AbstractExtensionTests {
 	private static final String SPRING_BOOT_VERSION = "3.3.0";
 
 	@ParameterizedTest
-	@ValueSource(strings = { "datadog", "dynatrace", "influx", "graphite", "new-relic", "otlp-metrics",
+	@ValueSource(strings = { "datadog", "dynatrace", "influx", "graphite", "new-relic", "otlp-metrics", "prometheus",
 			"distributed-tracing", "zipkin", "wavefront" })
 	void actuatorIsAddedWithObservabilityEntries(String dependency) {
 		assertThat(generateProject(SPRING_BOOT_VERSION, dependency)).mavenBuild()