diff --git a/packages/react-dom/src/events/getVendorPrefixedEventName.js b/packages/react-dom/src/events/getVendorPrefixedEventName.js
index 1ba369e9d14f2..bed5532fcbd3b 100644
--- a/packages/react-dom/src/events/getVendorPrefixedEventName.js
+++ b/packages/react-dom/src/events/getVendorPrefixedEventName.js
@@ -20,8 +20,6 @@ function makePrefixMap(styleProp, eventName) {
   prefixes[styleProp.toLowerCase()] = eventName.toLowerCase();
   prefixes['Webkit' + styleProp] = 'webkit' + eventName;
   prefixes['Moz' + styleProp] = 'moz' + eventName;
-  prefixes['ms' + styleProp] = 'MS' + eventName;
-  prefixes['O' + styleProp] = 'o' + eventName.toLowerCase();
 
   return prefixes;
 }