diff --git a/de4dot.code/deobfuscators/dotNET_Reactor/NativeImageUnpacker.cs b/de4dot.code/deobfuscators/dotNET_Reactor/NativeImageUnpacker.cs
index b12b0186..ac6961bd 100644
--- a/de4dot.code/deobfuscators/dotNET_Reactor/NativeImageUnpacker.cs
+++ b/de4dot.code/deobfuscators/dotNET_Reactor/NativeImageUnpacker.cs
@@ -58,6 +58,9 @@ namespace de4dot.deobfuscators.dotNET_Reactor {
 			if (count != inflatedSize)
 				return null;
 
+			if (BitConverter.ToInt16(inflatedData, 0) != 0x5A4D)
+				return null;
+
 			return inflatedData;
 		}