diff --git a/DS4Windows/DS4Windows.csproj b/DS4Windows/DS4Windows.csproj
index 9dcfb9e..a69e73e 100644
--- a/DS4Windows/DS4Windows.csproj
+++ b/DS4Windows/DS4Windows.csproj
@@ -87,6 +87,7 @@
     <UseVSHostingProcess>false</UseVSHostingProcess>
     <ErrorReport>prompt</ErrorReport>
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <DefineConstants>PLATFORM_X64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
     <DebugSymbols>true</DebugSymbols>
diff --git a/DS4Windows/HidLibrary/HidDevice.cs b/DS4Windows/HidLibrary/HidDevice.cs
index 4f71cf1..fcf496e 100644
--- a/DS4Windows/HidLibrary/HidDevice.cs
+++ b/DS4Windows/HidLibrary/HidDevice.cs
@@ -492,7 +492,12 @@ namespace DS4Windows
             else
             {
                 byte[] buffer = new byte[126];
-                NativeMethods.HidD_GetSerialNumberString(safeReadHandle.DangerousGetHandle(), buffer, (ulong)buffer.Length);
+#if PLATFORM_X64
+                ulong bufferLen = 126;
+#else
+                uint bufferLen = 126;
+#endif
+                NativeMethods.HidD_GetSerialNumberString(safeReadHandle.DangerousGetHandle(), buffer, bufferLen);
                 string MACAddr = System.Text.Encoding.Unicode.GetString(buffer).Replace("\0", string.Empty).ToUpper();
                 MACAddr = $"{MACAddr[0]}{MACAddr[1]}:{MACAddr[2]}{MACAddr[3]}:{MACAddr[4]}{MACAddr[5]}:{MACAddr[6]}{MACAddr[7]}:{MACAddr[8]}{MACAddr[9]}:{MACAddr[10]}{MACAddr[11]}";
                 serial = MACAddr;
diff --git a/DS4Windows/HidLibrary/NativeMethods.cs b/DS4Windows/HidLibrary/NativeMethods.cs
index 7af70cc..c6b30b9 100644
--- a/DS4Windows/HidLibrary/NativeMethods.cs
+++ b/DS4Windows/HidLibrary/NativeMethods.cs
@@ -391,7 +391,12 @@ namespace DS4Windows
 	    [DllImport("hid.dll")]
 	    static internal extern int HidP_GetValueCaps(short reportType, ref byte valueCaps, ref short valueCapsLength, IntPtr preparsedData);
 
+#if PLATFORM_X64
         [DllImport("hid.dll")]
         static internal extern bool HidD_GetSerialNumberString(IntPtr HidDeviceObject, byte[] Buffer, ulong BufferLength);
+#else
+        [DllImport("hid.dll")]
+        static internal extern bool HidD_GetSerialNumberString(IntPtr HidDeviceObject, byte[] Buffer, uint BufferLength);
+#endif
     }
 }