diff --git a/CCIProvider/TypeExtractor.cs b/CCIProvider/TypeExtractor.cs
index 19e64dda..b340fd52 100644
--- a/CCIProvider/TypeExtractor.cs
+++ b/CCIProvider/TypeExtractor.cs
@@ -972,7 +972,7 @@ private void ExtractParameters(IList<MethodParameter> dest, IEnumerable<Cci.IPar
 
 		private MethodParameterKind GetMethodParameterKind(Cci.IParameterTypeInformation parameterref)
 		{
-			var result = MethodParameterKind.In;
+			var result = MethodParameterKind.Normal;
 
 			if (parameterref.IsByReference) result = MethodParameterKind.Ref;
 
@@ -981,10 +981,11 @@ private MethodParameterKind GetMethodParameterKind(Cci.IParameterTypeInformation
 
 		private MethodParameterKind GetMethodParameterKind(Cci.IParameterDefinition parameterdef)
 		{
-			var result = MethodParameterKind.In;
+			var result = MethodParameterKind.Normal;
 
-			if (parameterdef.IsOut) result = MethodParameterKind.Out;
-			if (parameterdef.IsByReference) result = MethodParameterKind.Ref;
+			if (parameterdef.IsIn) result = MethodParameterKind.In;
+			else if (parameterdef.IsOut) result = MethodParameterKind.Out;
+			else if (parameterdef.IsByReference) result = MethodParameterKind.Ref;
 
 			return result;
 		}
diff --git a/MetadataProvider/AssemblyExtractor.cs b/MetadataProvider/AssemblyExtractor.cs
index 66787d90..cf3bb85d 100644
--- a/MetadataProvider/AssemblyExtractor.cs
+++ b/MetadataProvider/AssemblyExtractor.cs
@@ -549,13 +549,18 @@ private void ExtractParameter(SRM.MethodSignature<IType> signature, SRM.Paramete
 
 		private static MethodParameterKind GetParameterKind(SR.ParameterAttributes attributes, IType type)
 		{
-			var result = MethodParameterKind.In;
+			var result = MethodParameterKind.Normal;
 			var isOut = attributes.HasFlag(SR.ParameterAttributes.Out);
+			var isIn = attributes.HasFlag(SR.ParameterAttributes.In);
 
 			if (isOut)
 			{
 				result = MethodParameterKind.Out;
 			}
+			else if (isIn)
+			{
+				result = MethodParameterKind.In;
+			}
 			else if (type.IsPointer())
 			{
 				result = MethodParameterKind.Ref;
diff --git a/Model/ThreeAddressCode/Instructions.cs b/Model/ThreeAddressCode/Instructions.cs
index 270fde50..d38675a3 100644
--- a/Model/ThreeAddressCode/Instructions.cs
+++ b/Model/ThreeAddressCode/Instructions.cs
@@ -936,7 +936,8 @@ public override ISet<IVariable> ModifiedVariables
 				// We don't care here if the objects referenced by arguments could be modified.
 				foreach (var parameterInfo in this.Method.Parameters)
 				{
-					if (parameterInfo.Kind == MethodParameterKind.Ref)
+					if (parameterInfo.Kind == MethodParameterKind.Ref ||
+						parameterInfo.Kind == MethodParameterKind.Out)
 					{
 						var argument = this.Arguments[argumentIndex++];
 						result.Add(argument);
@@ -1017,7 +1018,8 @@ public override ISet<IVariable> ModifiedVariables
 				// We don't care here if the objects referenced by arguments could be modified.
 				foreach (var parameterInfo in this.Function.Parameters)
 				{
-					if (parameterInfo.Kind == MethodParameterKind.Ref)
+					if (parameterInfo.Kind == MethodParameterKind.Ref ||
+						parameterInfo.Kind == MethodParameterKind.Out)
 					{
 						var argument = this.Arguments[argumentIndex++];
 						result.Add(argument);
diff --git a/Model/Types/TypeDefinitions.cs b/Model/Types/TypeDefinitions.cs
index 27062ea7..34c59619 100644
--- a/Model/Types/TypeDefinitions.cs
+++ b/Model/Types/TypeDefinitions.cs
@@ -161,9 +161,10 @@ public override string ToString()
 
 	public enum MethodParameterKind
 	{
-		In,
-		Out,
-		Ref
+		Normal, // none
+		In, // in keyword
+		Out, // out keyword
+		Ref // ref keyword
 	}
 
 	public interface IMethodParameterReference
@@ -183,7 +184,7 @@ public MethodParameterReference(ushort index, IType type)
 		{
 			this.Index = index;
 			this.Type = type;
-			this.Kind = MethodParameterKind.In;
+			this.Kind = MethodParameterKind.Normal;
 		}
 
 		public override string ToString()
@@ -192,7 +193,8 @@ public override string ToString()
 
 			switch (this.Kind)
 			{
-				case MethodParameterKind.In: kind = string.Empty; break;
+				case MethodParameterKind.Normal: kind = String.Empty; break;
+				case MethodParameterKind.In: kind = "in "; break;
 				case MethodParameterKind.Out: kind = "out "; break;
 				case MethodParameterKind.Ref: kind = "ref "; break;
 
@@ -233,7 +235,7 @@ public MethodParameter(ushort index, string name, IType type)
 			this.Index = index;
 			this.Name = name;
 			this.Type = type;
-			this.Kind = MethodParameterKind.In;
+			this.Kind = MethodParameterKind.Normal;
 			this.Attributes = new HashSet<CustomAttribute>();
 		}
 
@@ -265,7 +267,8 @@ public override string ToString()
 
 			switch (this.Kind)
 			{
-				case MethodParameterKind.In: kind = string.Empty; break;
+				case MethodParameterKind.Normal: kind = string.Empty; break;
+				case MethodParameterKind.In: kind = "in "; break;
 				case MethodParameterKind.Out: kind = "out "; break;
 				case MethodParameterKind.Ref: kind = "ref "; break;