diff --git a/server/src/path_map.rs b/server/src/path_map.rs
index 138d4c40..af3f473c 100644
--- a/server/src/path_map.rs
+++ b/server/src/path_map.rs
@@ -129,4 +129,15 @@ impl<'a, T> Entry<'a, T> {
             children: HashSet::new(),
         }).value
     }
+}
+
+impl<'a, T> Entry<'a, T>
+    where T: Default
+{
+    pub fn or_default(self) -> &'a mut T {
+        &mut self.internal.or_insert(PathMapNode {
+            value: Default::default(),
+            children: HashSet::new(),
+        }).value
+    }
 }
\ No newline at end of file
diff --git a/server/src/rbx_session.rs b/server/src/rbx_session.rs
index 61768a81..6c0300c3 100644
--- a/server/src/rbx_session.rs
+++ b/server/src/rbx_session.rs
@@ -23,9 +23,9 @@ const INIT_SCRIPT: &str = "init.lua";
 const INIT_SERVER_SCRIPT: &str = "init.server.lua";
 const INIT_CLIENT_SCRIPT: &str = "init.client.lua";
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Default, Serialize, Deserialize)]
 pub struct MetadataPerPath {
-    pub instance_id: RbxId,
+    pub instance_id: Option<RbxId>,
     pub instance_name: Option<String>,
 }
 
@@ -91,7 +91,8 @@ impl RbxSession {
             trace!("Snapshotting path {}", path_to_snapshot.display());
 
             let path_metadata = self.metadata_per_path.get(&path_to_snapshot).unwrap();
-            let instance_id = path_metadata.instance_id;
+            let instance_id = path_metadata.instance_id
+                .expect("Instance did not exist in tree");
 
             // If this instance is a sync point, pull its name out of our
             // per-path metadata store.
diff --git a/server/src/rbx_snapshot.rs b/server/src/rbx_snapshot.rs
index 7eda3725..76cc63c5 100644
--- a/server/src/rbx_snapshot.rs
+++ b/server/src/rbx_snapshot.rs
@@ -8,7 +8,7 @@ use std::{
 
 use serde_derive::{Serialize, Deserialize};
 use maplit::hashmap;
-use rbx_tree::{RbxId, RbxTree, RbxValue, RbxInstanceProperties};
+use rbx_tree::{RbxTree, RbxValue, RbxInstanceProperties};
 use failure::Fail;
 
 use crate::{
@@ -141,11 +141,8 @@ fn snapshot_sync_point_node<'source>(
     };
 
     // Otherwise, we can log the name of the sync point we just snapshotted.
-    // TODO: Use entry API
-    metadata.metadata_per_path.insert(node.path.to_owned(), MetadataPerPath {
-        instance_id: RbxId::new(),
-        instance_name: Some(snapshot.name.clone().into_owned()),
-    });
+    let path_meta = metadata.metadata_per_path.entry(node.path.to_owned()).or_default();
+    path_meta.instance_name = Some(snapshot.name.clone().into_owned());
 
     Ok(Some(snapshot))
 }
diff --git a/server/src/snapshot_reconciler.rs b/server/src/snapshot_reconciler.rs
index 749e5f05..7874b7de 100644
--- a/server/src/snapshot_reconciler.rs
+++ b/server/src/snapshot_reconciler.rs
@@ -99,7 +99,7 @@ pub fn reify_root(
         // TODO: Use entry API instead?
         // metadata_per_path.entry()
         metadata_per_path.insert(source_path.clone(), MetadataPerPath {
-            instance_id: root_id,
+            instance_id: Some(root_id),
             instance_name: None,
         });
     }
@@ -129,8 +129,8 @@ pub fn reify_subtree(
     let id = tree.insert_instance(instance, parent_id);
 
     if let Some(source_path) = &snapshot.source_path {
-        // TODO: use entry API
-        // metadata_per_path.insert(source_path.clone(), id);
+        // TODO: Entry API
+        // let metadata = metadata_per_path.entry(source_path.clone(), id);
     }
 
     if let Some(metadata) = &snapshot.metadata {