diff --git a/app/server/lib/ActiveDoc.ts b/app/server/lib/ActiveDoc.ts
index 0725b154..a9c41f0c 100644
--- a/app/server/lib/ActiveDoc.ts
+++ b/app/server/lib/ActiveDoc.ts
@@ -300,6 +300,7 @@ export class ActiveDoc extends EventEmitter {
   @ActiveDoc.keepDocOpen
   public async createDoc(docSession: OptDocSession): Promise<ActiveDoc> {
     this.logDebug(docSession, "createDoc");
+    await this._docManager.storageManager.prepareToCreateDoc(this.docName);
     await this.docStorage.createFile();
     await this._rawPyCall('load_empty');
     const timezone = docSession.browserSettings ? docSession.browserSettings.timezone : DEFAULT_TIMEZONE;
diff --git a/app/server/lib/DocSnapshots.ts b/app/server/lib/DocSnapshots.ts
index 2b16cf3c..634e9dc7 100644
--- a/app/server/lib/DocSnapshots.ts
+++ b/app/server/lib/DocSnapshots.ts
@@ -110,6 +110,17 @@ export class DocSnapshotInventory implements IInventory {
   constructor(private _doc: ExternalStorage, private _meta: ExternalStorage,
               private _getFilename: (key: string) => Promise<string>) {}
 
+  /**
+   * Start keeping inventory for a new document.
+   */
+  public async create(key: string) {
+    await this._mutex.runExclusive(key, async() => {
+      const fname = await this._getFilename(key);
+      await this._saveToFile(fname, []);
+      this._needFlush.add(key);
+    });
+  }
+
   /**
    * Add a new snapshot of a document to the existing inventory.  A prevSnapshotId may
    * be supplied as a cross-check.  It will be matched against the most recent
@@ -126,7 +137,7 @@ export class DocSnapshotInventory implements IInventory {
     await this._mutex.runExclusive(key, async() => {
       const snapshots = await this._getSnapshots(key, prevSnapshotId);
       // Could be already added if reconstruction happened.
-      if (snapshots[0].snapshotId === snapshot.snapshotId) { return; }
+      if (snapshots[0] && snapshots[0].snapshotId === snapshot.snapshotId) { return; }
       this._normalizeMetadata(snapshot);
       snapshots.unshift(snapshot);
       const fname = await this._getFilename(key);
diff --git a/app/server/lib/DocStorageManager.ts b/app/server/lib/DocStorageManager.ts
index 9e6eade5..a4b44246 100644
--- a/app/server/lib/DocStorageManager.ts
+++ b/app/server/lib/DocStorageManager.ts
@@ -87,6 +87,10 @@ export class DocStorageManager implements IDocStorageManager {
    */
   public async prepareLocalDoc(docName: string, docSession: OptDocSession): Promise<boolean> { return false; }
 
+  public async prepareToCreateDoc(docName: string): Promise<void> {
+    // nothing to do
+  }
+
   /**
    * Returns a promise for the list of docNames to show in the doc list. For the file-based
    * storage, this will include all .grist files under the docsRoot.
@@ -212,7 +216,7 @@ export class DocStorageManager implements IDocStorageManager {
     // nothing to do
   }
 
-  public addToStorage(id: string): void {
+  public async addToStorage(id: string): Promise<void> {
     // nothing to do
   }
 
diff --git a/app/server/lib/HostedStorageManager.ts b/app/server/lib/HostedStorageManager.ts
index ec217c9d..a62d77c5 100644
--- a/app/server/lib/HostedStorageManager.ts
+++ b/app/server/lib/HostedStorageManager.ts
@@ -184,7 +184,8 @@ export class HostedStorageManager implements IDocStorageManager {
    */
   public async addToStorage(docId: string) {
     if (this._disableS3) { return; }
-    await this._ext.upload(docId, this.getPath(docId));
+    this._uploads.addOperation(docId);
+    await this._uploads.expediteOperationAndWait(docId);
   }
 
   public getPath(docName: string): string {
@@ -234,6 +235,13 @@ export class HostedStorageManager implements IDocStorageManager {
     }
   }
 
+  public async prepareToCreateDoc(docName: string): Promise<void> {
+    if (this._inventory) {
+      await this._inventory.create(docName);
+      this._onInventoryChange(docName);
+    }
+  }
+
   // Gets a copy of the document, eg. for downloading.  Returns full file path.
   // Copy won't change if edits are made to the document.  It is caller's responsibility
   // to delete the result.
@@ -656,10 +664,7 @@ export class HostedStorageManager implements IDocStorageManager {
         metadata
       }
       await this._inventory.add(docId, snapshot, prevSnapshotId);
-      const scheduled = this._pruner.requestPrune(docId);
-      if (!scheduled) {
-        await this._inventory.flush(docId);
-      }
+      await this._onInventoryChange(docId);
     } finally {
       // Clean up backup.
       // NOTE: fse.remove succeeds also when the file does not exist.
@@ -667,6 +672,14 @@ export class HostedStorageManager implements IDocStorageManager {
     }
   }
 
+  // Make sure inventory change is followed up on.
+  private async _onInventoryChange(docId: string) {
+    const scheduled = this._pruner.requestPrune(docId);
+    if (!scheduled) {
+      await this._inventory.flush(docId);
+    }
+  }
+
   // Extract actionHash, actionNum, and timezone from a document backup.
   private async _getDocMetadata(fname: string): Promise<{[key: string]: string}> {
     const result: Record<string, string> = {};
diff --git a/app/server/lib/IDocStorageManager.ts b/app/server/lib/IDocStorageManager.ts
index fe708919..a1dbcca4 100644
--- a/app/server/lib/IDocStorageManager.ts
+++ b/app/server/lib/IDocStorageManager.ts
@@ -12,6 +12,7 @@ export interface IDocStorageManager {
   // In the current implementation, it is called in the context of an
   // AsyncCreate[docName].
   prepareLocalDoc(docName: string, docSession: OptDocSession): Promise<boolean>;
+  prepareToCreateDoc(docName: string): Promise<void>;
 
   listDocs(): Promise<DocEntry[]>;
   deleteDoc(docName: string, deletePermanently?: boolean): Promise<void>;
@@ -24,7 +25,7 @@ export interface IDocStorageManager {
   // If reason is set to 'edit' the user-facing timestamp on the document should be updated.
   markAsChanged(docName: string, reason?: 'edit'): void;
   testReopenStorage(): void;                // restart storage during tests
-  addToStorage(docName: string): void;      // add a new local document to storage
+  addToStorage(docName: string): Promise<void>;  // add a new local document to storage
   prepareToCloseStorage(): void;            // speed up sync with remote store
   getCopy(docName: string): Promise<string>;  // get an immutable copy of a document