diff --git a/src/components/views/rooms/BasicMessageComposer.tsx b/src/components/views/rooms/BasicMessageComposer.tsx
index 2d21e9f616..061dfe2703 100644
--- a/src/components/views/rooms/BasicMessageComposer.tsx
+++ b/src/components/views/rooms/BasicMessageComposer.tsx
@@ -129,6 +129,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     private modifiedFlag = false;
     private isIMEComposing = false;
     private hasTextSelected = false;
+    private readonly isSafari: boolean;
 
     private _isCaretAtEnd = false;
     private lastCaret!: DocumentOffset;
@@ -149,6 +150,9 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
             showVisualBell: false,
         };
 
+        const ua = navigator.userAgent.toLowerCase();
+        this.isSafari = ua.includes("safari/") && !ua.includes("chrome/");
+
         this.useMarkdownHandle = SettingsStore.watchSetting(
             "MessageComposerInput.useMarkdown",
             null,
@@ -308,10 +312,7 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
 
         // however, doing this async seems to break things in Safari for some reason, so browser sniff.
 
-        const ua = navigator.userAgent.toLowerCase();
-        const isSafari = ua.includes("safari/") && !ua.includes("chrome/");
-
-        if (isSafari) {
+        if (this.isSafari) {
             this.onInput({ inputType: "insertCompositionText" });
         } else {
             Promise.resolve().then(() => {
@@ -324,6 +325,9 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
         // checking the event.isComposing flag just in case any browser out there
         // emits events related to the composition after compositionend
         // has been fired
+
+        // From https://www.stum.de/2016/06/24/handling-ime-events-in-javascript/
+        // Safari emits an additional keyDown after compositionend
         return !!(this.isIMEComposing || (event.nativeEvent && event.nativeEvent.isComposing));
     }
 
@@ -503,6 +507,11 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
 
     private onKeyDown = (event: React.KeyboardEvent): void => {
         if (!this.editorRef.current) return;
+        if (this.isSafari && event.which == 229) {
+            // Swallow the extra keyDown by Safari
+            event.stopPropagation();
+            return;
+        }
         const model = this.props.model;
         let handled = false;