diff --git a/cryptest.nmake b/cryptest.nmake
index 5da9a2a5..8aa855af 100644
--- a/cryptest.nmake
+++ b/cryptest.nmake
@@ -53,7 +53,7 @@ LDLIBS =
 !IF "$(PLATFORM)" == ""
 !IF "$(PROCESSOR_ARCHITECTURE)" == "x86" 
 PLATFORM = x86
-!ELSEIF "$(PROCESSOR_ARCHITECTURE)" == "x64"
+!ELSEIF "$(PROCESSOR_ARCHITECTURE)" == "x64" || "$(PROCESSOR_ARCHITECTURE)" == "AMD64"
 PLATFORM = x64
 !ELSE
 !ERROR "Unknown platform"