--- a/dom/media/webspeech/synth/windows/SapiService.cpp
+++ b/dom/media/webspeech/synth/windows/SapiService.cpp
@@ -369,23 +369,32 @@ SapiService::Speak(const nsAString& aTex
   // Set the pitch using xml
   nsAutoString xml;
   xml.AssignLiteral("<pitch absmiddle=\"");
   // absmiddle doesn't allow float type
   xml.AppendInt(static_cast<int32_t>(aPitch * 10.0f - 10.0f));
   xml.AppendLiteral("\">");
   uint32_t textOffset = xml.Length();
 
-  const char16_t* escapedText =
-    nsEscapeHTML2(aText.BeginReading(), aText.Length());
-  if (!escapedText) {
-    return NS_ERROR_OUT_OF_MEMORY;
+  for (size_t i = 0; i < aText.Length(); i++) {
+    switch (aText[i]) {
+      case '&':
+        xml.AppendLiteral("&amp;");
+        break;
+      case '<':
+        xml.AppendLiteral("&lt;");
+        break;
+      case '>':
+        xml.AppendLiteral("&gt;");
+        break;
+      default:
+        xml.Append(aText[i]);
+        break;
+    }
   }
-  xml.Append(escapedText);
-  free((void*)escapedText);
 
   xml.AppendLiteral("</pitch>");
 
   RefPtr<SapiCallback> callback =
     new SapiCallback(aTask, spVoice, textOffset, aText.Length());
 
   // The last three parameters doesn't matter for an indirect service
   nsresult rv = aTask->Setup(callback, 0, 0, 0);