diff --git a/lib/concurrent/thread_safe/util/array_hash_rbx.rb b/lib/concurrent/thread_safe/util/array_hash_rbx.rb
index 3fc2a38a9..52de9dacc 100644
--- a/lib/concurrent/thread_safe/util/array_hash_rbx.rb
+++ b/lib/concurrent/thread_safe/util/array_hash_rbx.rb
@@ -18,11 +18,22 @@ def self.allocate
         end
 
         klass.superclass.instance_methods(false).each do |method|
-          klass.class_eval <<-RUBY, __FILE__, __LINE__ + 1
-            def #{method}(*args)
-              @_monitor.synchronize { super }
-            end
-          RUBY
+          case method
+          when :new_range, :new_reserved
+            klass.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+              def #{method}(*args)
+                obj = super
+                obj.send(:_mon_initialize)
+                obj
+              end
+            RUBY
+          else
+            klass.class_eval <<-RUBY, __FILE__, __LINE__ + 1
+              def #{method}(*args)
+                @_monitor.synchronize { super }
+              end
+            RUBY
+          end
         end
       end
     end
diff --git a/spec/concurrent/array_spec.rb b/spec/concurrent/array_spec.rb
index 4dd3bbf63..7f03ab760 100644
--- a/spec/concurrent/array_spec.rb
+++ b/spec/concurrent/array_spec.rb
@@ -14,5 +14,15 @@ module Concurrent
         end
       end.map(&:join)
     end
+
+    describe '#slice' do
+      # This is mostly relevant on Rubinius and Truffle
+      it 'correctly initializes the monitor' do
+        ary.concat([0, 1, 2, 3, 4, 5, 6, 7, 8])
+
+        sliced = ary.slice!(0..2)
+        expect { sliced[0] }.not_to raise_error
+      end
+    end
   end
 end