diff --git a/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Declarations.cs b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Declarations.cs
index 0e98995f8..aa641476e 100644
--- a/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Declarations.cs
+++ b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Declarations.cs
@@ -180,6 +180,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Msl
                     {
                         // TODO: check if it's needed
                         context.AppendLine("float4 position [[position]];");
+                        context.AppendLine("bool front_facing [[front_facing]];");
                     }
 
                     foreach (var ioDefinition in inputs.OrderBy(x => x.Location))
diff --git a/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs
index b306e8283..6c11b70dc 100644
--- a/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs
+++ b/src/Ryujinx.Graphics.Shader/CodeGen/Msl/Instructions/IoMap.cs
@@ -23,7 +23,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Msl.Instructions
                 IoVariable.ClipDistance => ("clip_distance", AggregateType.Array | AggregateType.FP32),
                 IoVariable.FragmentOutputColor => ($"out.color{location}", AggregateType.Vector4 | AggregateType.FP32),
                 IoVariable.FragmentOutputDepth => ("out.depth", AggregateType.FP32),
-                IoVariable.FrontFacing => ("front_facing", AggregateType.Bool),
+                IoVariable.FrontFacing => ("in.front_facing", AggregateType.Bool),
                 IoVariable.GlobalId => ("thread_position_in_grid", AggregateType.Vector3 | AggregateType.U32),
                 IoVariable.InstanceId => ("instance_id", AggregateType.S32),
                 IoVariable.InvocationId => ("INVOCATION_ID", AggregateType.S32),