diff --git a/Cargo.lock b/Cargo.lock
index 3a47a6d..5c51647 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1161,6 +1161,7 @@ dependencies = [
  "harmony",
  "harmony_cli",
  "harmony_macros",
+ "serde_yaml",
  "tokio",
  "url",
 ]
diff --git a/examples/monitoring/Cargo.toml b/examples/monitoring/Cargo.toml
index 1c35330..1f27939 100644
--- a/examples/monitoring/Cargo.toml
+++ b/examples/monitoring/Cargo.toml
@@ -9,5 +9,6 @@ license.workspace = true
 harmony = { version = "0.1.0", path = "../../harmony" }
 harmony_cli = { version = "0.1.0", path = "../../harmony_cli" }
 harmony_macros = { version = "0.1.0", path = "../../harmony_macros" }
+serde_yaml.workspace = true
 tokio.workspace = true
 url.workspace = true
diff --git a/examples/monitoring/src/main.rs b/examples/monitoring/src/main.rs
index e7d5f22..bb48ccf 100644
--- a/examples/monitoring/src/main.rs
+++ b/examples/monitoring/src/main.rs
@@ -19,6 +19,7 @@ use harmony::{
 };
 
 use harmony_macros::http_scheme;
+use serde_yaml::{Mapping, Value};
 
 #[tokio::main]
 async fn main() {
@@ -55,13 +56,24 @@ async fn main() {
         relabelings: vec![],
     };
 
+    let mut selector = Mapping::new();
+    selector.insert(
+        Value::from("matchExpressions"),
+        serde_yaml::to_value(vec![Selector {
+            key: "monitored".to_string(),
+            operator: "In".to_string(),
+            values: vec!["test-service-1".to_string()],
+        }])
+        .expect("couldn't create mapping value"),
+    );
+
     let service_monitor = ServiceMonitor {
-        name: "test service monitor".to_string(),
+        name: "test-service-monitor".to_string(),
         additional_labels: None,
         job_label: None,
         target_labels: vec![],
         pod_target_labels: vec![],
-        selector: None,
+        selector: selector,
         match_labels: None,
         namespace_selector: None,
         endpoints: vec![service_monitor_endpoint],
diff --git a/harmony/src/modules/monitoring/kube_prometheus/types.rs b/harmony/src/modules/monitoring/kube_prometheus/types.rs
index d3942ba..60c8168 100644
--- a/harmony/src/modules/monitoring/kube_prometheus/types.rs
+++ b/harmony/src/modules/monitoring/kube_prometheus/types.rs
@@ -143,6 +143,14 @@ pub struct ServiceMonitorEndpoint {
     pub relabelings: Vec<Mapping>,
 }
 
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Selector {
+    pub key: String,
+    pub operator: String,
+    pub values: Vec<String>,
+}
+
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct ServiceMonitor {
@@ -170,7 +178,7 @@ pub struct ServiceMonitor {
     //       values:
     //         - example-service-1
     //         - example-service-2
-    pub selector: Option<Mapping>,
+    pub selector: Mapping,
 
     //   # label selector for services
     pub match_labels: Option<Mapping>,