diff --git a/lib/Sidef/Parser.pm b/lib/Sidef/Parser.pm
index 0fb8043c1..519600d97 100644
--- a/lib/Sidef/Parser.pm
+++ b/lib/Sidef/Parser.pm
@@ -145,9 +145,12 @@ package Sidef::Parser {
             built_in_classes => {
                 map { $_ => 1 }
                   qw(
-                  File FileHandle
-                  Dir DirHandle
-                  Arr Array Pair
+                  File
+                  FileHandle
+                  Dir
+                  DirHandle
+                  Arr Array
+                  Pair
                   MultiArray MultiArr
                   Hash
                   Str String
@@ -165,6 +168,7 @@ package Sidef::Parser {
                   Sig SIG
                   Regex
                   Time
+                  Perl
                   Sidef
                   Parser
                   Block
diff --git a/scripts/amb_nested_loops.sf b/scripts/amb_nested_loops.sf
index b60009947..5352b2dbe 100644
--- a/scripts/amb_nested_loops.sf
+++ b/scripts/amb_nested_loops.sf
@@ -15,7 +15,7 @@ var code = { |*arr|
 func main () {
 
     var alg = (
-        try   { require 'Algorithm::Loops'->() }
+        try   { frequire 'Algorithm::Loops' }
         catch { STDERR.print("** Algorithm::Loops is not installed!\n"); return }
     );