diff --git a/src/AST/Enumeration.cs b/src/AST/Enumeration.cs
index dc98b888..b76ccb51 100644
--- a/src/AST/Enumeration.cs
+++ b/src/AST/Enumeration.cs
@@ -22,10 +22,18 @@ namespace CppSharp.AST
         public class Item : INamedDecl
         {
             public string Name { get; set; }
-            public long Value;
+            public ulong Value;
             public string Expression;
             public string Comment;
             public bool ExplicitValue = true;
+
+            public bool IsHexadecimal
+            {
+                get
+                { 
+                    return Expression.Contains("0x") || Expression.Contains("0X");
+                }
+            }
         }
 
         public Enumeration()
@@ -42,6 +50,14 @@ namespace CppSharp.AST
             return this;
         }
 
+        public string GetItemValueAsString(Item item)
+        {
+            var format = item.IsHexadecimal ? "x" : string.Empty;
+            var value = BuiltinType.IsUnsigned ? item.Value.ToString(format) :
+                ((long)item.Value).ToString(format);
+            return item.IsHexadecimal ? "0x" + value : value;
+        }
+
         public Enumeration SetFlags()
         {
             Modifiers |= EnumModifiers.Flags;
diff --git a/src/AST/Type.cs b/src/AST/Type.cs
index 074bcfe5..13207ffe 100644
--- a/src/AST/Type.cs
+++ b/src/AST/Type.cs
@@ -534,6 +534,24 @@ namespace CppSharp.AST
             Type = type;
         }
 
+        public bool IsUnsigned
+        {
+            get
+            {
+                switch (Type)
+                {
+                case PrimitiveType.Bool:
+                case PrimitiveType.UInt8:
+                case PrimitiveType.UInt16:
+                case PrimitiveType.UInt32:
+                case PrimitiveType.UInt64:
+                    return true;
+                }
+
+                return false;
+            }
+        }
+
         // Primitive type of built-in type.
         public PrimitiveType Type;
 
diff --git a/src/Generator/Generators/CLI/CLIHeadersTemplate.cs b/src/Generator/Generators/CLI/CLIHeadersTemplate.cs
index 7b30fd30..8279046c 100644
--- a/src/Generator/Generators/CLI/CLIHeadersTemplate.cs
+++ b/src/Generator/Generators/CLI/CLIHeadersTemplate.cs
@@ -608,7 +608,8 @@ namespace CppSharp.Generators.CLI
                 var item = @enum.Items[i];
                 GenerateInlineSummary(item.Comment);
                 if (item.ExplicitValue)
-                    Write(String.Format("{0} = {1}", SafeIdentifier(item.Name), item.Value));
+                    Write(String.Format("{0} = {1}", SafeIdentifier(item.Name),
+                        @enum.GetItemValueAsString(item)));
                 else
                     Write(String.Format("{0}", SafeIdentifier(item.Name)));
 
diff --git a/src/Generator/Generators/CSharp/CSharpTextTemplate.cs b/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
index 46ae6de0..5f61d3ae 100644
--- a/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
+++ b/src/Generator/Generators/CSharp/CSharpTextTemplate.cs
@@ -1601,8 +1601,9 @@ namespace CppSharp.Generators.CSharp
                 var item = @enum.Items[i];
                 GenerateInlineSummary(item.Comment);
 
+                var value = @enum.GetItemValueAsString(item);
                 Write(item.ExplicitValue
-                          ? string.Format("{0} = {1}", SafeIdentifier(item.Name), item.Value)
+                          ? string.Format("{0} = {1}", SafeIdentifier(item.Name), value)
                           : string.Format("{0}", SafeIdentifier(item.Name)));
 
                 if (i < @enum.Items.Count - 1)
diff --git a/src/Generator/Library.cs b/src/Generator/Library.cs
index e53c86e9..86e6a72b 100644
--- a/src/Generator/Library.cs
+++ b/src/Generator/Library.cs
@@ -114,12 +114,12 @@ namespace CppSharp
             return long.TryParse(num, out val);
         }
 
-        static long ParseMacroExpression(string expression)
+        static ulong ParseMacroExpression(string expression)
         {
             // TODO: Handle string expressions
 
             long val;
-            return ParseToNumber(expression, out val) ? val : 0;
+            return ParseToNumber(expression, out val) ? (ulong)val : 0;
         }
 
         public static Enumeration GenerateEnumFromMacros(this Library library, string name,
diff --git a/src/Generator/Utils/Utils.cs b/src/Generator/Utils/Utils.cs
index 6c21a470..86694451 100644
--- a/src/Generator/Utils/Utils.cs
+++ b/src/Generator/Utils/Utils.cs
@@ -9,7 +9,7 @@ namespace CppSharp
 {
     public static class IntHelpers
     {
-        public static bool IsPowerOfTwo(this long x)
+        public static bool IsPowerOfTwo(this ulong x)
         {
             return (x != 0) && ((x & (x - 1)) == 0);
         }
diff --git a/src/Parser/Parser.cpp b/src/Parser/Parser.cpp
index e3af86fd..b69d64c0 100644
--- a/src/Parser/Parser.cpp
+++ b/src/Parser/Parser.cpp
@@ -1218,9 +1218,10 @@ CppSharp::AST::Enumeration^ Parser::WalkEnum(clang::EnumDecl* ED)
 
         auto EnumItem = gcnew CppSharp::AST::Enumeration::Item();
         EnumItem->Name = marshalString<E_UTF8>(ECD->getNameAsString());
-        EnumItem->Value = (int) ECD->getInitVal().getLimitedValue();
+        auto Value = ECD->getInitVal();
+        EnumItem->Value = Value.isSigned() ? Value.getSExtValue()
+            : Value.getZExtValue();
         EnumItem->Comment = marshalString<E_UTF8>(BriefText);
-        //EnumItem->ExplicitValue = ECD->getExplicitValue();
 
         std::string Text;
         if (GetDeclText(ECD->getSourceRange(), Text))