diff --git a/src/coreclr/tools/Common/TypeSystem/Interop/IL/Marshaller.cs b/src/coreclr/tools/Common/TypeSystem/Interop/IL/Marshaller.cs
index 764e6e8bb8e570..b13711716b8179 100644
--- a/src/coreclr/tools/Common/TypeSystem/Interop/IL/Marshaller.cs
+++ b/src/coreclr/tools/Common/TypeSystem/Interop/IL/Marshaller.cs
@@ -1474,7 +1474,7 @@ private bool ShouldBePinned
             get
             {
                 return MarshalDirection == MarshalDirection.Forward
-                    && MarshallerType != MarshallerType.Field
+                    && MarshallerType == MarshallerType.Argument
                     && !IsManagedByRef
                     && In
                     && !Out;
@@ -1672,7 +1672,11 @@ protected override void TransformManagedToNative(ILCodeStream codeStream)
         {
             ILEmitter emitter = _ilCodeStreams.Emitter;
 
-            if (In && !Out && !IsManagedByRef)
+            if (MarshalDirection == MarshalDirection.Forward
+                && MarshallerType == MarshallerType.Argument
+                && !IsManagedByRef
+                && In
+                && !Out)
             {
                 TypeDesc marshallerIn = MarshallerIn;
 
diff --git a/src/tests/nativeaot/SmokeTests/PInvoke/PInvoke.cs b/src/tests/nativeaot/SmokeTests/PInvoke/PInvoke.cs
index b8e6b8d57db354..52205934d046d3 100644
--- a/src/tests/nativeaot/SmokeTests/PInvoke/PInvoke.cs
+++ b/src/tests/nativeaot/SmokeTests/PInvoke/PInvoke.cs
@@ -702,6 +702,8 @@ public struct SequentialStruct
             public float f2;
             [MarshalAs(UnmanagedType.LPStr)]
             public String f3;
+            [MarshalAs(UnmanagedType.LPUTF8Str)]
+            public String f4;
         }
 
         [StructLayout(LayoutKind.Sequential)]
@@ -713,6 +715,8 @@ public class SequentialClass
             public float f2;
             [MarshalAs(UnmanagedType.LPStr)]
             public String f3;
+            [MarshalAs(UnmanagedType.LPUTF8Str)]
+            public String f4;
         }
 
         // A second struct with the same name but nested. Regression test against native types being mangled into
@@ -824,15 +828,16 @@ private static void TestStruct()
             ss.f1 = 1;
             ss.f2 = 10.0f;
             ss.f3 = "Hello";
+            ss.f4 = "Hola";
 
             ThrowIfNotEquals(true, StructTest(ss), "Struct marshalling scenario1 failed.");
 
             StructTest_ByRef(ref ss);
-            ThrowIfNotEquals(true,  ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp"), "Struct marshalling scenario2 failed.");
+            ThrowIfNotEquals(true,  ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp") && ss.f4.Equals("Ipmb"), "Struct marshalling scenario2 failed.");
 
             SequentialStruct ss2 = new SequentialStruct();
             StructTest_ByOut(out ss2);
-            ThrowIfNotEquals(true, ss2.f0 == 1 && ss2.f1 == 1.0 &&  ss2.f2 == 1.0 && ss2.f3.Equals("0123456"), "Struct marshalling scenario3 failed.");
+            ThrowIfNotEquals(true, ss2.f0 == 1 && ss2.f1 == 1.0 &&  ss2.f2 == 1.0 && ss2.f3.Equals("0123456") && ss2.f4.Equals("789"), "Struct marshalling scenario3 failed.");
 
             NesterOfSequentialStruct.SequentialStruct ss3 = new NesterOfSequentialStruct.SequentialStruct();
             ss3.f1 = 10.0f;
@@ -861,6 +866,7 @@ private static void TestStruct()
                 ssa[i].f1 = i;
                 ssa[i].f2 = i*i;
                 ssa[i].f3 = i.LowLevelToString();
+                ssa[i].f4 = "u8" + i.LowLevelToString();
             }
             ThrowIfNotEquals(true, StructTest_Array(ssa, ssa.Length), "Array of struct marshalling failed");
 
@@ -923,9 +929,10 @@ private static void TestLayoutClassPtr()
             ss.f1 = 1;
             ss.f2 = 10.0f;
             ss.f3 = "Hello";
+            ss.f4 = "Hola";
 
             ClassTest(ss);
-            ThrowIfNotEquals(true, ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp"), "LayoutClassPtr marshalling scenario1 failed.");
+            ThrowIfNotEquals(true, ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp") && ss.f4.Equals("Ipmb"), "LayoutClassPtr marshalling scenario1 failed.");
         }
 
 #if OPTIMIZED_MODE_WITHOUT_SCANNER
@@ -955,20 +962,22 @@ private static void TestAsAny()
             sc.f1 = 1;
             sc.f2 = 10.0f;
             sc.f3 = "Hello";
+            sc.f4 = "Hola";
 
             AsAnyTest(sc);
-            ThrowIfNotEquals(true, sc.f1 == 2 && sc.f2 == 11.0 && sc.f3.Equals("Ifmmp"), "AsAny marshalling scenario1 failed.");
+            ThrowIfNotEquals(true, sc.f1 == 2 && sc.f2 == 11.0 && sc.f3.Equals("Ifmmp") && sc.f4.Equals("Ipmb"), "AsAny marshalling scenario1 failed.");
 
             SequentialStruct ss = new SequentialStruct();
             ss.f0 = 100;
             ss.f1 = 1;
             ss.f2 = 10.0f;
             ss.f3 = "Hello";
+            ss.f4 = "Hola";
 
             object o = ss;
             AsAnyTest(o);
             ss = (SequentialStruct)o;
-            ThrowIfNotEquals(true, ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp"), "AsAny marshalling scenario2 failed.");
+            ThrowIfNotEquals(true, ss.f1 == 2 && ss.f2 == 11.0 && ss.f3.Equals("Ifmmp") && sc.f4.Equals("Ipmb"), "AsAny marshalling scenario2 failed.");
         }
 
         private static void TestLayoutClass()
diff --git a/src/tests/nativeaot/SmokeTests/PInvoke/PInvokeNative.cpp b/src/tests/nativeaot/SmokeTests/PInvoke/PInvokeNative.cpp
index 7412274680bcfd..480209d3b2560a 100644
--- a/src/tests/nativeaot/SmokeTests/PInvoke/PInvokeNative.cpp
+++ b/src/tests/nativeaot/SmokeTests/PInvoke/PInvokeNative.cpp
@@ -471,6 +471,7 @@ struct NativeSequentialStruct
     int a;
     float b;
     char *str;
+    char *u8str;
 };
 
 struct NativeSequentialStruct2
@@ -494,6 +495,9 @@ DLL_EXPORT bool __stdcall StructTest(NativeSequentialStruct nss)
     if (!CompareAnsiString(nss.str, "Hello"))
         return false;
 
+    if (!CompareAnsiString(nss.u8str, "Hola"))
+        return false;
+
     return true;
 }
 
@@ -519,6 +523,13 @@ DLL_EXPORT void __stdcall StructTest_ByRef(NativeSequentialStruct *nss)
         *p = *p + 1;
         p++;
     }
+
+    p = nss->u8str;
+    while (*p != '\0')
+    {
+        *p = *p + 1;
+        p++;
+    }
 }
 
 DLL_EXPORT void __stdcall StructTest_ByOut(NativeSequentialStruct *nss)
@@ -529,7 +540,7 @@ DLL_EXPORT void __stdcall StructTest_ByOut(NativeSequentialStruct *nss)
 
     int arrSize = 7;
     char *p;
-    p = (char *)MemAlloc(sizeof(char) * arrSize);
+    p = (char *)MemAlloc(sizeof(char) * arrSize + 1);
 
     for (int i = 0; i < arrSize; i++)
     {
@@ -537,6 +548,10 @@ DLL_EXPORT void __stdcall StructTest_ByOut(NativeSequentialStruct *nss)
     }
     *(p + arrSize) = '\0';
     nss->str = p;
+
+    p = (char *)MemAlloc(sizeof(char) * 4);
+    strcpy(p, "789");
+    nss->u8str = p;
 }
 
 DLL_EXPORT bool __stdcall StructTest_Array(NativeSequentialStruct *nss, int length)
@@ -558,6 +573,11 @@ DLL_EXPORT bool __stdcall StructTest_Array(NativeSequentialStruct *nss, int leng
 
         if (CompareAnsiString(expected, nss[i].str) == 0)
             return false;
+
+        sprintf(expected, "u8%d", i);
+
+        if (CompareAnsiString(expected, nss[i].u8str) == 0)
+            return false;
     }
     return true;
 }