diff --git a/reference/opt/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag b/reference/opt/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
index 6116deab..1cb7aa70 100644
--- a/reference/opt/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
+++ b/reference/opt/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
@@ -69,7 +69,7 @@ fragment main0_out main0(main0_in in [[stage_in]])
     c[1] = in.c_1;
     e[0] = in.e_0;
     e[1] = in.e_1;
-    out.FragColor = float4(float(int(in.a.x)), float(in.b.x), float2(float(uint(c[1])), float(e[0].w)) + in.d.xy);
+    out.FragColor = float4(float(int(short(in.a.x))), float(int(in.b.x)), float2(float(uint(c[1])), float(e[0].w)) + in.d.xy);
     return out;
 }
 
diff --git a/reference/opt/shaders-msl/vert/signedness-mismatch.shader-inputs.vert b/reference/opt/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
index d6e056be..56e00199 100644
--- a/reference/opt/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
+++ b/reference/opt/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
@@ -68,7 +68,7 @@ vertex main0_out main0(main0_in in [[stage_in]])
     c[1] = in.c_1;
     d[0] = in.d_0;
     d[1] = in.d_1;
-    out.gl_Position = float4(float(int(in.a.x)), float(in.b.x), float(uint(c[1])), float(d[0].w));
+    out.gl_Position = float4(float(int(short(in.a.x))), float(int(in.b.x)), float(uint(c[1])), float(d[0].w));
     return out;
 }
 
diff --git a/reference/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag b/reference/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
index 6116deab..1cb7aa70 100644
--- a/reference/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
+++ b/reference/shaders-msl/frag/vecsize-mismatch.shader-inputs.frag
@@ -69,7 +69,7 @@ fragment main0_out main0(main0_in in [[stage_in]])
     c[1] = in.c_1;
     e[0] = in.e_0;
     e[1] = in.e_1;
-    out.FragColor = float4(float(int(in.a.x)), float(in.b.x), float2(float(uint(c[1])), float(e[0].w)) + in.d.xy);
+    out.FragColor = float4(float(int(short(in.a.x))), float(int(in.b.x)), float2(float(uint(c[1])), float(e[0].w)) + in.d.xy);
     return out;
 }
 
diff --git a/reference/shaders-msl/vert/signedness-mismatch.shader-inputs.vert b/reference/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
index d6e056be..56e00199 100644
--- a/reference/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
+++ b/reference/shaders-msl/vert/signedness-mismatch.shader-inputs.vert
@@ -68,7 +68,7 @@ vertex main0_out main0(main0_in in [[stage_in]])
     c[1] = in.c_1;
     d[0] = in.d_0;
     d[1] = in.d_1;
-    out.gl_Position = float4(float(int(in.a.x)), float(in.b.x), float(uint(c[1])), float(d[0].w));
+    out.gl_Position = float4(float(int(short(in.a.x))), float(int(in.b.x)), float(uint(c[1])), float(d[0].w));
     return out;
 }
 
diff --git a/spirv_msl.cpp b/spirv_msl.cpp
index cb6eac92..22ab1900 100644
--- a/spirv_msl.cpp
+++ b/spirv_msl.cpp
@@ -15685,9 +15685,19 @@ void CompilerMSL::cast_from_variable_load(uint32_t source_id, std::string &expr,
 	if (var && var->storage == StorageClassWorkgroup && expr_type.basetype == SPIRType::Boolean)
 		expr = join(type_to_glsl(expr_type), "(", expr, ")");
 
-	// Only interested in standalone builtin variables.
+	// Only interested in standalone builtin variables in the switch below.
 	if (!has_decoration(source_id, DecorationBuiltIn))
+	{
+		// If the backing variable does not match our expected sign, we can fix it up here.
+		// See ensure_correct_input_type().
+		if (var && var->storage == StorageClassInput)
+		{
+			auto &base_type = get<SPIRType>(var->basetype);
+			if (base_type.basetype != SPIRType::Struct && expr_type.basetype != base_type.basetype)
+				expr = join(type_to_glsl(expr_type), "(", expr, ")");
+		}
 		return;
+	}
 
 	auto builtin = static_cast<BuiltIn>(get_decoration(source_id, DecorationBuiltIn));
 	auto expected_type = expr_type.basetype;