diff --git a/radicle-cob/src/change_graph.rs b/radicle-cob/src/change_graph.rs
index c98a90b4..f7fbc8a3 100644
--- a/radicle-cob/src/change_graph.rs
+++ b/radicle-cob/src/change_graph.rs
@@ -130,8 +130,9 @@ impl GraphBuilder {
         let resource_commit = *change.resource();
         let commit_id = commit.id;
 
-        self.graph.node(commit_id, change);
-
+        if !self.graph.contains(&commit_id) {
+            self.graph.node(commit_id, change);
+        }
         commit.parents.into_iter().filter_map(move |parent| {
             if parent.id != resource_commit && !self.graph.has_dependency(&commit_id, &parent.id) {
                 Some((parent, commit_id))
diff --git a/radicle-dag/src/lib.rs b/radicle-dag/src/lib.rs
index ce40811d..6bd95f0d 100644
--- a/radicle-dag/src/lib.rs
+++ b/radicle-dag/src/lib.rs
@@ -103,6 +103,11 @@ impl<K: Eq + Copy + Hash, V> Dag<K, V> {
         }
     }
 
+    /// Check if the graph contains a node.
+    pub fn contains(&self, key: &K) -> bool {
+        self.graph.contains_key(key)
+    }
+
     /// Get a node.
     pub fn get(&self, key: &K) -> Option<&Node<K, V>> {
         self.graph.get(key)