diff --git a/build/VStudio/winfsp.net.csproj b/build/VStudio/winfsp.net.csproj
index 695a13e0..e8b9e06c 100644
--- a/build/VStudio/winfsp.net.csproj
+++ b/build/VStudio/winfsp.net.csproj
@@ -24,7 +24,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <AllowUnsafeBlocks>false</AllowUnsafeBlocks>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
diff --git a/src/dotnet/FileSystem.cs b/src/dotnet/FileSystem.cs
index fc076f8e..4aaccc87 100644
--- a/src/dotnet/FileSystem.cs
+++ b/src/dotnet/FileSystem.cs
@@ -112,33 +112,11 @@ namespace Fsp
         }
         public void SetPrefix(String Prefix)
         {
-            int Size = Prefix.Length;
-            if (Size > VolumeParams.PrefixSize - 1)
-                Size = VolumeParams.PrefixSize - 1;
-            unsafe
-            {
-                fixed (UInt16 *P = _VolumeParams.Prefix)
-                {
-                    for (int I = 0; Size > I; I++)
-                        P[I] = Prefix[I];
-                    P[Size] = '\0';
-                }
-            }
+            _VolumeParams.Prefix = Prefix;
         }
         public void SetFileSystemName(String FileSystemName)
         {
-            int Size = FileSystemName.Length;
-            if (Size > VolumeParams.FileSystemNameSize - 1)
-                Size = VolumeParams.FileSystemNameSize - 1;
-            unsafe
-            {
-                fixed (UInt16 *P = _VolumeParams.FileSystemName)
-                {
-                    for (int I = 0; Size > I; I++)
-                        P[I] = FileSystemName[I];
-                    P[Size] = '\0';
-                }
-            }
+            _VolumeParams.FileSystemName = FileSystemName;
         }
 
         private VolumeParams _VolumeParams;
diff --git a/src/dotnet/Interop.cs b/src/dotnet/Interop.cs
index 1436fa6a..c365dd86 100644
--- a/src/dotnet/Interop.cs
+++ b/src/dotnet/Interop.cs
@@ -22,7 +22,7 @@ using System.Security;
 namespace Fsp.Interop
 {
 
-    [StructLayout(LayoutKind.Sequential)]
+    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
     internal struct VolumeParams
     {
         /* const */
@@ -56,17 +56,22 @@ namespace Fsp.Interop
         internal UInt32 IrpCapacity;
         internal UInt32 FileInfoTimeout;
         internal UInt32 Flags;
-        internal unsafe fixed UInt16 Prefix[PrefixSize];
-        internal unsafe fixed UInt16 FileSystemName[FileSystemNameSize];
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = PrefixSize)]
+        internal String Prefix;
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = FileSystemNameSize)]
+        internal String FileSystemName;
     }
 
-    [StructLayout(LayoutKind.Sequential)]
+    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
     internal struct VolumeInfo
     {
+        internal const int VolumeLabelSize = 32;
+
         internal UInt64 TotalSize;
         internal UInt64 FreeSize;
         internal UInt16 VolumeLabelLength;
-        internal unsafe fixed UInt16 VolumeLabel[32];
+        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = VolumeLabelSize)]
+        internal String VolumeLabel;
     }
 
     [StructLayout(LayoutKind.Sequential)]
@@ -97,7 +102,7 @@ namespace Fsp.Interop
     {
         internal UInt16 Size;
         internal FileInfo FileInfo;
-        internal unsafe fixed Byte Padding[24];
+        //internal unsafe fixed Byte Padding[24];
         //internal unsafe fixed UInt16 FileNameBuf[];
     }
 
@@ -304,8 +309,7 @@ namespace Fsp.Interop
             UInt32 Length,
             out UInt32 PBytesTransferred);
 
-        internal unsafe fixed ulong Reserved[40];
-            /* cannot use IntPtr with fixed; on 32-bit struct will be too long, but that's ok */
+        //internal unsafe fixed IntPtr Reserved[40];
     }
 
     [SuppressUnmanagedCodeSecurity]