diff --git a/examples/monitoring/src/main.rs b/examples/monitoring/src/main.rs
index 59e9f6b..c029055 100644
--- a/examples/monitoring/src/main.rs
+++ b/examples/monitoring/src/main.rs
@@ -21,7 +21,6 @@ use harmony::{
 };
 
 use harmony_macros::http_scheme;
-use serde_yaml::{Mapping, Value};
 
 #[tokio::main]
 async fn main() {
@@ -58,24 +57,20 @@ async fn main() {
         relabelings: vec![],
     };
 
-    let mut selector = HashMap::new();
-    selector.insert(
-        "matchExpressions".to_string(),
-        vec![Selector {
-            key: "monitored".to_string(),
-            operator: "In".to_string(),
-            values: vec!["test-service-1".to_string()],
-        }],
-    );
-
     let service_monitor = ServiceMonitor {
         name: "test-service-monitor".to_string(),
         additional_labels: None,
         job_label: None,
         target_labels: vec![],
         pod_target_labels: vec![],
-        selector: selector,
-        match_labels: None,
+        selector: Selector {
+            match_labels: None,
+            match_expressions: vec![MatchExpression {
+                key: "test".to_string(),
+                operator: "In".to_string(),
+                values: vec!["test-service".to_string()],
+            }],
+        },
         namespace_selector: None,
         endpoints: vec![service_monitor_endpoint],
         fallback_scrape_protocol: None,
diff --git a/harmony/src/modules/monitoring/kube_prometheus/types.rs b/harmony/src/modules/monitoring/kube_prometheus/types.rs
index 59d6ebc..9e1f96b 100644
--- a/harmony/src/modules/monitoring/kube_prometheus/types.rs
+++ b/harmony/src/modules/monitoring/kube_prometheus/types.rs
@@ -145,12 +145,20 @@ pub struct ServiceMonitorEndpoint {
 
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
-pub struct Selector {
+pub struct MatchExpression {
     pub key: String,
     pub operator: String,
     pub values: Vec<String>,
 }
 
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Selector {
+    //   # label selector for services
+    pub match_labels: Option<HashMap<String, String>>,
+    pub match_expressions: Vec<MatchExpression>,
+}
+
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct ServiceMonitor {
@@ -178,10 +186,7 @@ pub struct ServiceMonitor {
     //       values:
     //         - example-service-1
     //         - example-service-2
-    pub selector: HashMap<String, Vec<Selector>>,
-
-    //   # label selector for services
-    pub match_labels: Option<Mapping>,
+    pub selector: Selector,
 
     // # Namespaces from which services are selected
     //   # Match any namespace