diff --git a/src/components/views/rooms/Autocomplete.tsx b/src/components/views/rooms/Autocomplete.tsx
index af33fb2d9e..423b5c6272 100644
--- a/src/components/views/rooms/Autocomplete.tsx
+++ b/src/components/views/rooms/Autocomplete.tsx
@@ -10,6 +10,7 @@ import React, { createRef, KeyboardEvent, RefObject } from "react";
 import classNames from "classnames";
 import { flatMap } from "lodash";
 import { Room } from "matrix-js-sdk/src/matrix";
+import { defer } from "matrix-js-sdk/src/utils";
 
 import Autocompleter, { ICompletion, ISelectionRange, IProviderCompletions } from "../../../autocomplete/Autocompleter";
 import SettingsStore from "../../../settings/SettingsStore";
@@ -127,18 +128,21 @@ export default class Autocomplete extends React.PureComponent<IProps, IState> {
     }
 
     private async processQuery(query: string, selection: ISelectionRange): Promise<void> {
-        return this.autocompleter
-            ?.getCompletions(query, selection, this.state.forceComplete, MAX_PROVIDER_MATCHES)
-            .then((completions) => {
-                // Only ever process the completions for the most recent query being processed
-                if (query !== this.queryRequested) {
-                    return;
-                }
-                this.processCompletions(completions);
-            });
+        if (!this.autocompleter) return;
+        const completions = await this.autocompleter.getCompletions(
+            query,
+            selection,
+            this.state.forceComplete,
+            MAX_PROVIDER_MATCHES,
+        );
+        // Only ever process the completions for the most recent query being processed
+        if (query !== this.queryRequested) {
+            return;
+        }
+        await this.processCompletions(completions);
     }
 
-    private processCompletions(completions: IProviderCompletions[]): void {
+    private async processCompletions(completions: IProviderCompletions[]): Promise<void> {
         const completionList = flatMap(completions, (provider) => provider.completions);
 
         // Reset selection when completion list becomes empty.
@@ -169,14 +173,19 @@ export default class Autocomplete extends React.PureComponent<IProps, IState> {
             }
         }
 
-        this.setState({
-            completions,
-            completionList,
-            selectionOffset,
-            hide,
-            // Force complete is turned off each time since we can't edit the query in that case
-            forceComplete: false,
-        });
+        const deferred = defer<void>();
+        this.setState(
+            {
+                completions,
+                completionList,
+                selectionOffset,
+                hide,
+                // Force complete is turned off each time since we can't edit the query in that case
+                forceComplete: false,
+            },
+            deferred.resolve,
+        );
+        await deferred.promise;
     }
 
     public hasSelection(): boolean {