diff --git a/Steamless.API/PE32/NativeApi32.cs b/Steamless.API/PE32/NativeApi32.cs
index 4f65b13..d18ac19 100644
--- a/Steamless.API/PE32/NativeApi32.cs
+++ b/Steamless.API/PE32/NativeApi32.cs
@@ -608,5 +608,15 @@ namespace Steamless.API.PE32
             public uint SizeOfZeroFill;
             public uint Characteristics;
         }
+
+        /// <summary>
+        /// imagehlp!MapFileAndChecksum
+        /// </summary>
+        /// <param name="Filename"></param>
+        /// <param name="HeaderSum"></param>
+        /// <param name="CheckSum"></param>
+        /// <returns></returns>
+        [DllImport("imagehlp.dll", CharSet = CharSet.Auto)]
+        public static extern int MapFileAndCheckSum(string Filename, out uint HeaderSum, out uint CheckSum);
     }
 }
\ No newline at end of file
diff --git a/Steamless.API/PE64/NativeApi64.cs b/Steamless.API/PE64/NativeApi64.cs
index 7b04209..e601193 100644
--- a/Steamless.API/PE64/NativeApi64.cs
+++ b/Steamless.API/PE64/NativeApi64.cs
@@ -604,5 +604,15 @@ namespace Steamless.API.PE64
             public uint SizeOfZeroFill;
             public uint Characteristics;
         }
+
+        /// <summary>
+        /// imagehlp!MapFileAndChecksum
+        /// </summary>
+        /// <param name="Filename"></param>
+        /// <param name="HeaderSum"></param>
+        /// <param name="CheckSum"></param>
+        /// <returns></returns>
+        [DllImport("imagehlp.dll", CharSet = CharSet.Auto)]
+        public static extern int MapFileAndCheckSum(string Filename, out uint HeaderSum, out uint CheckSum);
     }
 }
\ No newline at end of file