diff --git a/ui/jquery.ui.dialog.js b/ui/jquery.ui.dialog.js
index b01907acf..16095292c 100644
--- a/ui/jquery.ui.dialog.js
+++ b/ui/jquery.ui.dialog.js
@@ -342,7 +342,10 @@ $.widget( "ui.dialog", {
 			}
 		});
 
-		this.uiDialogTitlebarClose = $("<button></button>")
+		// support: IE
+		// Use type="button" to prevent enter keypresses in textboxes from closing the
+		// dialog in IE (#9312)
+		this.uiDialogTitlebarClose = $( "<button type='button'></button>" )
 			.button({
 				label: this.options.closeText,
 				icons: {