diff --git a/lib/rex/random_identifier/generator.rb b/lib/rex/random_identifier/generator.rb
index 17763e1..3b9de78 100644
--- a/lib/rex/random_identifier/generator.rb
+++ b/lib/rex/random_identifier/generator.rb
@@ -427,7 +427,8 @@ def generate(len = nil)
   #
   # @return [Boolean] Is identifier forbidden?
   def forbid_id?(ident = nil)
-    ident.nil? or @opts[:forbidden].any? {|f| f.match(/^#{ident}$/i) }
+    return true if ident.nil?
+    @opts[:forbidden].any? { |f| f.casecmp?(ident) }
   end
 
 end
diff --git a/spec/rex/random_identifier/generator_spec.rb b/spec/rex/random_identifier/generator_spec.rb
index aed9881..bd58c55 100644
--- a/spec/rex/random_identifier/generator_spec.rb
+++ b/spec/rex/random_identifier/generator_spec.rb
@@ -182,6 +182,20 @@
           { ident: '_', expected: true },
           { ident: 'session', expected: true },
         ]
+      },
+      {
+        language: :powershell,
+        tests: [
+          { ident: 'if', expected: true },
+          { ident: 'while', expected: true },
+          { ident: 'function', expected: true },
+          { ident: 'param', expected: true },
+          { ident: 'array', expected: true },
+          { ident: 'string', expected: true },
+          { ident: 'args', expected: true },
+          { ident: 'eventargs', expected: true },
+          { ident: 'foovar', expected: false },
+        ]
       }
     ].each do |scenario|
       context "when the language is #{scenario[:language]}" do