diff --git a/pixel.cpp b/pixel.cpp
index 1d062ad191accf39740bb8570d8b9dbb64583555..a56c140c9b4ac87c7d844ff144cee18712f4196a 100644
--- a/pixel.cpp
+++ b/pixel.cpp
@@ -18,7 +18,7 @@ void decrypt(int data);
 // void toAscii(char *c);
 
 
-void pixel(char key[3],
+void pixel(char key[16],
         ap_int<32> selector,
 		ap_int<32> position1,
 		ap_int<32> position2,