diff --git a/core/util.inc.php b/core/util.inc.php
index 14fdbc8f..3e434b62 100644
--- a/core/util.inc.php
+++ b/core/util.inc.php
@@ -283,6 +283,12 @@ function array_remove($array, $to_remove) {
 	return $a2;
 }
 
+function array_add($array, $element) { 
+	$array[] = $element; 
+	$array = array_unique($array); 
+	return $array; 
+} 
+
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
 * Event API                                                                 *
diff --git a/ext/tag_list/theme.php b/ext/tag_list/theme.php
index fd2d5226..3439f16d 100644
--- a/ext/tag_list/theme.php
+++ b/ext/tag_list/theme.php
@@ -136,7 +136,7 @@ class TagListTheme extends Themelet {
 		}
 		else {
 			$tags = array_remove($tags, "-$tag");
-			$tags = array_push($tags, $tag);
+			$tags = array_add($tags, $tag);
 			return "<a href='".$this->tag_link(join(' ', $tags))."' title='Add' rel='nofollow'>A</a>";
 		}
 	}
@@ -147,7 +147,7 @@ class TagListTheme extends Themelet {
 		}
 		else {
 			$tags = array_remove($tags, $tag);
-			$tags = array_push($tags, "-$tag");
+			$tags = array_add($tags, "-$tag");
 			return "<a href='".$this->tag_link(join(' ', $tags))."' title='Subtract' rel='nofollow'>S</a>";
 		}
 	}