diff --git a/src/AST/Type.cs b/src/AST/Type.cs
index ac9870bf..f196a8ba 100644
--- a/src/AST/Type.cs
+++ b/src/AST/Type.cs
@@ -665,8 +665,8 @@ namespace CppSharp.AST
         UInt32,
         Long,
         ULong,
-        Int64,
-        UInt64,
+        LongLong,
+        ULongLong,
         Float,
         Double,
         IntPtr,
@@ -699,7 +699,7 @@ namespace CppSharp.AST
                 case PrimitiveType.UShort:
                 case PrimitiveType.UInt32:
                 case PrimitiveType.ULong:
-                case PrimitiveType.UInt64:
+                case PrimitiveType.ULongLong:
                     return true;
                 }
 
diff --git a/src/Core/Parser/ASTConverter.cs b/src/Core/Parser/ASTConverter.cs
index 839769e7..36328af7 100644
--- a/src/Core/Parser/ASTConverter.cs
+++ b/src/Core/Parser/ASTConverter.cs
@@ -572,10 +572,10 @@ namespace CppSharp
                     return AST.PrimitiveType.Long;
                 case PrimitiveType.ULong:
                     return AST.PrimitiveType.ULong;
-                case PrimitiveType.Int64:
-                    return AST.PrimitiveType.Int64;
-                case PrimitiveType.UInt64:
-                    return AST.PrimitiveType.UInt64;
+                case PrimitiveType.LongLong:
+                    return AST.PrimitiveType.LongLong;
+                case PrimitiveType.ULongLong:
+                    return AST.PrimitiveType.ULongLong;
                 case PrimitiveType.Float:
                     return AST.PrimitiveType.Float;
                 case PrimitiveType.Double:
diff --git a/src/CppParser/AST.h b/src/CppParser/AST.h
index 5874cf74..a4f54dc7 100644
--- a/src/CppParser/AST.h
+++ b/src/CppParser/AST.h
@@ -242,8 +242,8 @@ enum struct PrimitiveType
     UInt32,
     Long,
     ULong,
-    Int64,
-    UInt64,
+    LongLong,
+    ULongLong,
     Float,
     Double,
     IntPtr
diff --git a/src/CppParser/Parser.cpp b/src/CppParser/Parser.cpp
index cea7a057..d8cfec54 100644
--- a/src/CppParser/Parser.cpp
+++ b/src/CppParser/Parser.cpp
@@ -1338,8 +1338,8 @@ static PrimitiveType WalkBuiltinType(const clang::BuiltinType* Builtin)
     case clang::BuiltinType::Long: return PrimitiveType::Long;
     case clang::BuiltinType::ULong: return PrimitiveType::ULong;
     
-    case clang::BuiltinType::LongLong: return PrimitiveType::Int64;
-    case clang::BuiltinType::ULongLong: return PrimitiveType::UInt64;
+    case clang::BuiltinType::LongLong: return PrimitiveType::LongLong;
+    case clang::BuiltinType::ULongLong: return PrimitiveType::ULongLong;
 
     case clang::BuiltinType::Float: return PrimitiveType::Float;
     case clang::BuiltinType::Double: return PrimitiveType::Double;
diff --git a/src/Generator/Generators/CLI/CLIMarshal.cs b/src/Generator/Generators/CLI/CLIMarshal.cs
index 344075d2..90d186b4 100644
--- a/src/Generator/Generators/CLI/CLIMarshal.cs
+++ b/src/Generator/Generators/CLI/CLIMarshal.cs
@@ -164,8 +164,8 @@ namespace CppSharp.Generators.CLI
                 case PrimitiveType.UInt32:
                 case PrimitiveType.Long:
                 case PrimitiveType.ULong:
-                case PrimitiveType.Int64:
-                case PrimitiveType.UInt64:
+                case PrimitiveType.LongLong:
+                case PrimitiveType.ULongLong:
                 case PrimitiveType.Float:
                 case PrimitiveType.Double:
                 case PrimitiveType.Null:
@@ -505,8 +505,8 @@ namespace CppSharp.Generators.CLI
                 case PrimitiveType.UInt32:
                 case PrimitiveType.Long:
                 case PrimitiveType.ULong:
-                case PrimitiveType.Int64:
-                case PrimitiveType.UInt64:
+                case PrimitiveType.LongLong:
+                case PrimitiveType.ULongLong:
                 case PrimitiveType.Float:
                 case PrimitiveType.Double:
                     Context.Return.Write(Context.Parameter.Name);
diff --git a/src/Generator/Generators/CLI/CLITypePrinter.cs b/src/Generator/Generators/CLI/CLITypePrinter.cs
index 41b0c6f4..4ff79a8f 100644
--- a/src/Generator/Generators/CLI/CLITypePrinter.cs
+++ b/src/Generator/Generators/CLI/CLITypePrinter.cs
@@ -197,8 +197,8 @@ namespace CppSharp.Generators.CLI
                 case PrimitiveType.UInt32: return "unsigned int";
                 case PrimitiveType.Long: return "long";
                 case PrimitiveType.ULong: return "unsigned long";
-                case PrimitiveType.Int64: return "long long";
-                case PrimitiveType.UInt64: return "unsigned long long";
+                case PrimitiveType.LongLong: return "long long";
+                case PrimitiveType.ULongLong: return "unsigned long long";
                 case PrimitiveType.Float: return "float";
                 case PrimitiveType.Double: return "double";
                 case PrimitiveType.IntPtr: return "IntPtr";
diff --git a/src/Generator/Generators/CSharp/CSharpMarshal.cs b/src/Generator/Generators/CSharp/CSharpMarshal.cs
index b4dabd19..35eab5d2 100644
--- a/src/Generator/Generators/CSharp/CSharpMarshal.cs
+++ b/src/Generator/Generators/CSharp/CSharpMarshal.cs
@@ -195,8 +195,8 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.UInt32:
                 case PrimitiveType.Long:
                 case PrimitiveType.ULong:
-                case PrimitiveType.Int64:
-                case PrimitiveType.UInt64:
+                case PrimitiveType.LongLong:
+                case PrimitiveType.ULongLong:
                 case PrimitiveType.Float:
                 case PrimitiveType.Double:
                 case PrimitiveType.WideChar:
@@ -517,8 +517,8 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.UInt32:
                 case PrimitiveType.Long:
                 case PrimitiveType.ULong:
-                case PrimitiveType.Int64:
-                case PrimitiveType.UInt64:
+                case PrimitiveType.LongLong:
+                case PrimitiveType.ULongLong:
                 case PrimitiveType.Float:
                 case PrimitiveType.Double:
                 case PrimitiveType.WideChar:
diff --git a/src/Generator/Generators/CSharp/CSharpTypePrinter.cs b/src/Generator/Generators/CSharp/CSharpTypePrinter.cs
index dd37cbda..fb1d819c 100644
--- a/src/Generator/Generators/CSharp/CSharpTypePrinter.cs
+++ b/src/Generator/Generators/CSharp/CSharpTypePrinter.cs
@@ -394,8 +394,8 @@ namespace CppSharp.Generators.CSharp
                 case PrimitiveType.UInt32: return "uint";
                 case PrimitiveType.Long: return "int";
                 case PrimitiveType.ULong: return "uint";
-                case PrimitiveType.Int64: return "long";
-                case PrimitiveType.UInt64: return "ulong";
+                case PrimitiveType.LongLong: return "long";
+                case PrimitiveType.ULongLong: return "ulong";
                 case PrimitiveType.Float: return "float";
                 case PrimitiveType.Double: return "double";
                 case PrimitiveType.IntPtr: return "global::System.IntPtr";
diff --git a/src/Generator/Types/CppTypePrinter.cs b/src/Generator/Types/CppTypePrinter.cs
index 2ea130aa..ee04e1b3 100644
--- a/src/Generator/Types/CppTypePrinter.cs
+++ b/src/Generator/Types/CppTypePrinter.cs
@@ -112,8 +112,8 @@ namespace CppSharp.Types
                 case PrimitiveType.UInt32: return "unsigned int";
                 case PrimitiveType.Long: return "long";
                 case PrimitiveType.ULong: return "unsigned long";
-                case PrimitiveType.Int64: return "long long";
-                case PrimitiveType.UInt64: return "unsigned long long";
+                case PrimitiveType.LongLong: return "long long";
+                case PrimitiveType.ULongLong: return "unsigned long long";
                 case PrimitiveType.Float: return "float";
                 case PrimitiveType.Double: return "double";
                 case PrimitiveType.IntPtr: return "void*";
diff --git a/src/Parser/Parser.cpp b/src/Parser/Parser.cpp
index 90abe880..d4fa163a 100644
--- a/src/Parser/Parser.cpp
+++ b/src/Parser/Parser.cpp
@@ -1344,8 +1344,8 @@ static CppSharp::AST::PrimitiveType WalkBuiltinType(const clang::BuiltinType* Bu
     case clang::BuiltinType::Long: return PrimitiveType::Long;
     case clang::BuiltinType::ULong: return PrimitiveType::ULong;
     
-    case clang::BuiltinType::LongLong: return PrimitiveType::Int64;
-    case clang::BuiltinType::ULongLong: return PrimitiveType::UInt64;
+    case clang::BuiltinType::LongLong: return PrimitiveType::LongLong;
+    case clang::BuiltinType::ULongLong: return PrimitiveType::ULongLong;
 
     case clang::BuiltinType::Float: return PrimitiveType::Float;
     case clang::BuiltinType::Double: return PrimitiveType::Double;