diff --git a/lib/Sabberworm/CSS/Value/Size.php b/lib/Sabberworm/CSS/Value/Size.php
index f65246b5..a813f929 100644
--- a/lib/Sabberworm/CSS/Value/Size.php
+++ b/lib/Sabberworm/CSS/Value/Size.php
@@ -61,8 +61,7 @@ private static function getSizeUnits() {
 				self::$SIZE_UNITS[$iSize][strtolower($val)] = $val;
 			}
 
-			// FIXME: Should we not order the longest units first?
-			ksort(self::$SIZE_UNITS, SORT_NUMERIC);
+			krsort(self::$SIZE_UNITS, SORT_NUMERIC);
 		}
 
 		return self::$SIZE_UNITS;