diff --git a/core/hash.rb b/core/hash.rb
index f3bd0491c1..38de80e48f 100644
--- a/core/hash.rb
+++ b/core/hash.rb
@@ -166,12 +166,13 @@ def delete(key)
       var map  = #{self}.map, result;
 
       if (result = map[key]) {
-        result = bucket[1];
+        result = result[1];
 
         delete map[key];
+        return result;
       }
 
-      return result;
+      return nil;
     }
   end
 
diff --git a/spec/core/hash/constructor_spec.rb b/spec/core/hash/constructor_spec.rb
new file mode 100644
index 0000000000..b28c6a5e97
--- /dev/null
+++ b/spec/core/hash/constructor_spec.rb
@@ -0,0 +1,13 @@
+describe "Hash.[]" do
+  describe "passed zero arguments" do
+    it "returns an empty hash" do
+      Hash[].should == {}
+    end
+  end
+
+  it "creates a Hash; values can be provided as the argument list" do
+    Hash[:a, 1, :b, 2].should == { :a => 1, :b => 2 }
+    Hash[].should == {}
+    Hash[:a, 1, :b, {:c => 2}].should == {:a => 1, :b => {:c => 2}}
+  end
+end
\ No newline at end of file
diff --git a/spec/core/hash/default_proc_spec.rb b/spec/core/hash/default_proc_spec.rb
new file mode 100644
index 0000000000..e50adba60b
--- /dev/null
+++ b/spec/core/hash/default_proc_spec.rb
@@ -0,0 +1,20 @@
+describe "Hash#default_proc" do
+  it "returns the block passed to Hash.new" do
+    h = Hash.new { |i| 'Paris' }
+    p = h.default_proc
+    p.call(1).should == 'Paris'
+  end
+
+  it "returns nil if no block was passed to proc" do
+    {}.default_proc.should == nil
+  end
+end
+
+describe "Hash#default_proc=" do
+  it "replaces the block passed to Hash.new" do
+    h = Hash.new { |i| 'Paris' }
+    h.default_proc = Proc.new { 'Montreal' }
+    p = h.default_proc
+    p.call(1).should == 'Montreal'
+  end
+end
\ No newline at end of file
diff --git a/spec/core/hash/default_spec.rb b/spec/core/hash/default_spec.rb
index 8819addf68..c7dfc74124 100644
--- a/spec/core/hash/default_spec.rb
+++ b/spec/core/hash/default_spec.rb
@@ -6,4 +6,12 @@
     Hash.new.default.should == nil
     Hash.new.default(4).should == nil
   end
+end
+
+describe "Hash#default=" do
+  it "sets the default value" do
+    h = {}
+    h.default = 99
+    h.default.should == 99
+  end
 end
\ No newline at end of file
diff --git a/spec/core/hash/delete_spec.rb b/spec/core/hash/delete_spec.rb
new file mode 100644
index 0000000000..3d06637a98
--- /dev/null
+++ b/spec/core/hash/delete_spec.rb
@@ -0,0 +1,11 @@
+describe "Hash#delete" do
+  it "removes the entry and returns the deleted value" do
+    h = {a: 5, b: 2}
+    h.delete(:b).should == 2
+    h.should == {a: 5}
+  end
+
+  it "returns nil if the key is not found" do
+    {}.delete(:a).should == nil
+  end
+end
\ No newline at end of file
diff --git a/spec/core/hash/dup_spec.rb b/spec/core/hash/dup_spec.rb
new file mode 100644
index 0000000000..9494f7e568
--- /dev/null
+++ b/spec/core/hash/dup_spec.rb
@@ -0,0 +1,10 @@
+describe "Hash#dup" do
+  it "copies instance variable but not the objects they refer to" do
+    hash = {'key' => 'value'}
+
+    clone = hash.dup
+
+    clone.should == hash
+    clone.object_id.should_not == hash.object_id
+  end
+end
\ No newline at end of file
diff --git a/spec/core/hash/reject_spec.rb b/spec/core/hash/reject_spec.rb
new file mode 100644
index 0000000000..37c3be3363
--- /dev/null
+++ b/spec/core/hash/reject_spec.rb
@@ -0,0 +1,18 @@
+describe "Hash#reject" do
+  it "returns a new hash removing keys for which the block yields true" do
+    h = {1=>false, 2=>true, 3=>false, 4=>true}
+    h.reject { |k,v| v }.keys.should == [1,3]
+  end
+
+  it "is equivalent to hsh.dup.delete_if" do
+    h = {:a => 'a', :b => 'b', :c => 'd'}
+    h.reject { |k,v| k == 'd' }.should == (h.dup.delete_if { |k, v| k == 'd' })
+
+    all_args_reject = []
+    all_args_delete_if = []
+    h = {1 => 2, 3 => 4}
+    h.reject { |*args| all_args_reject << args }
+    h.delete_if { |*args| all_args_delete_if << args }
+    all_args_reject.should == all_args_delete_if
+  end
+end
\ No newline at end of file
diff --git a/spec/core/hash/to_a_spec.rb b/spec/core/hash/to_a_spec.rb
new file mode 100644
index 0000000000..de4a53ba32
--- /dev/null
+++ b/spec/core/hash/to_a_spec.rb
@@ -0,0 +1,13 @@
+describe "Hash#to_a" do
+  it "returns a list of [key, value] pairs with same order as each()" do
+    h = {:a => 1, 1 => :a, 3 => :b, :b => 5}
+    pairs = []
+
+    h.each_pair do |key, value|
+      pairs << [key, value]
+    end
+
+    h.to_a.should be_kind_of(Array)
+    h.to_a.should == pairs
+  end
+end
\ No newline at end of file