diff --git a/autoload/emmet/lang/css.vim b/autoload/emmet/lang/css.vim
index 3a6baff..3a9ca93 100644
--- a/autoload/emmet/lang/css.vim
+++ b/autoload/emmet/lang/css.vim
@@ -60,6 +60,10 @@ function! emmet#lang#css#parseIntoTree(abbr, type) abort
               let value .= v
             elseif v =~# 'e$'
               let value .= substitute(v, 'e$', 'em', '')
+            elseif v =~# 'em$'
+              let value .= v
+            elseif v =~# 'ex$'
+              let value .= v
             elseif v =~# 'x$'
               let value .= substitute(v, 'x$', 'ex', '')
             elseif v =~# 'em$'