diff --git a/src/transforms/dedupe/transform.rs b/src/transforms/dedupe/transform.rs
index 9c1432d2abb12..17bdbe30c2478 100644
--- a/src/transforms/dedupe/transform.rs
+++ b/src/transforms/dedupe/transform.rs
@@ -137,3 +137,103 @@ impl TaskTransform<Event> for Dedupe {
         Box::pin(task.filter_map(move |v| ready(inner.transform_one(v))))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::event::LogEvent;
+    use crate::test_util::components::assert_transform_compliance;
+    use crate::transforms::dedupe::common::{default_cache_config, FieldMatchConfig};
+    use crate::transforms::dedupe::config::DedupeConfig;
+    use crate::transforms::test::create_topology;
+    use tokio::sync::mpsc;
+    use tokio_stream::wrappers::ReceiverStream;
+    use vector_lib::lookup::lookup_v2::ConfigTargetPath;
+    use vrl::value::Value;
+
+    pub fn assert_eq_values(left: LogEvent, right: LogEvent) {
+        let inner_left = left.into_parts().0;
+        let inner_right = right.into_parts().0;
+        assert_eq!(inner_left, inner_right);
+    }
+
+    #[tokio::test]
+    async fn default_match() {
+        let config = DedupeConfig {
+            cache: default_cache_config(),
+            fields: None,
+        };
+
+        assert_transform_compliance(async move {
+            let (tx, rx) = mpsc::channel(1);
+
+            let (topology, mut out) = create_topology(ReceiverStream::new(rx), config).await;
+
+            let event1 = LogEvent::from(btreemap! {
+                "message" => "foo",
+                "host" => "bar",
+                "timestamp" => "t1",
+            });
+            tx.send(event1.clone().into()).await.unwrap();
+            let output = out.recv().await.unwrap().into_log();
+            assert_eq_values(event1.clone(), output);
+
+            let event2 = event1.clone();
+            tx.send(event2.into()).await.unwrap();
+
+            let mut event3 = event1.clone();
+            event3.insert("message", Value::from("another"));
+            tx.send(event3.clone().into()).await.unwrap();
+
+            let output = out.recv().await.unwrap().into_log();
+            assert_eq_values(event3, output);
+
+            drop(tx);
+            topology.stop().await;
+            assert_eq!(out.recv().await, None);
+        })
+        .await
+    }
+
+    #[tokio::test]
+    async fn custom_match() {
+        let config = DedupeConfig {
+            cache: default_cache_config(),
+            fields: Some(FieldMatchConfig::MatchFields(vec![
+                ConfigTargetPath::from("a"),
+                ConfigTargetPath::from("b"),
+            ])),
+        };
+
+        assert_transform_compliance(async move {
+            let (tx, rx) = mpsc::channel(1);
+
+            let (topology, mut out) = create_topology(ReceiverStream::new(rx), config).await;
+
+            let event1 = LogEvent::from(btreemap! {
+                "message" => "foo",
+                "a" => 1,
+                "b" => 2,
+            });
+            tx.send(event1.clone().into()).await.unwrap();
+            let output = out.recv().await.unwrap().into_log();
+            assert_eq_values(event1.clone(), output);
+
+            let event2 = event1.clone();
+            tx.send(event2.into()).await.unwrap();
+
+            let event3 = LogEvent::from(btreemap! {
+                "message" => "bar",
+                "a" => 3,
+                "b" => 2,
+            });
+            tx.send(event3.clone().into()).await.unwrap();
+            let output = out.recv().await.unwrap().into_log();
+            assert_eq_values(event3, output);
+
+            drop(tx);
+            topology.stop().await;
+            assert_eq!(out.recv().await, None);
+        })
+        .await
+    }
+}