diff --git a/src/wp-admin/js/editor-expand.js b/src/wp-admin/js/editor-expand.js
index 1fa72828b5..260ee25513 100644
--- a/src/wp-admin/js/editor-expand.js
+++ b/src/wp-admin/js/editor-expand.js
@@ -195,6 +195,14 @@ jQuery( document ).ready( function($) {
 				return;
 			}
 
+			// Bail on special keys.
+			if ( key <= 47 && ! ( key === VK.SPACEBAR || key === VK.ENTER || key === VK.DELETE || key === VK.BACKSPACE || key === VK.UP || key === VK.LEFT || key === VK.DOWN || key === VK.UP ) ) {
+				return;
+			// OS keys, function keys, num lock, scroll lock
+			} else if ( ( key >= 91 && key <= 93 ) || ( key >= 112 && key <= 123 ) || key === 144 || key === 145 ) {
+				return;
+			}
+
 			cursorTop = offset.top + editor.iframeElement.getBoundingClientRect().top;
 			cursorBottom = cursorTop + offset.height;
 			cursorTop = cursorTop - buffer;