diff --git a/FATCATMain/AFP.h b/FATCATMain/AFP.h
index 8182419..d5379f6 100644
--- a/FATCATMain/AFP.h
+++ b/FATCATMain/AFP.h
@@ -100,7 +100,7 @@ class AFP
 		}
 
 		//assign a given afp to this
-		void	operator = (AFP &afp) 
+		void	operator = (const AFP &afp) 
 		{
 			i = afp.i;
 			j = afp.j;
diff --git a/FATCATMain/Align0.h b/FATCATMain/Align0.h
index fd2a8b9..aa14f35 100644
--- a/FATCATMain/Align0.h
+++ b/FATCATMain/Align0.h
@@ -6,6 +6,7 @@
 //2. a similarity matrix (any type, eg. defined by structural similarity)
 #ifndef ALIGN0_H
 #define ALIGN0_H
+#include <cstring>
 #include "basic.h"
 
 class ALIGN0