diff --git a/pixel.cpp b/pixel.cpp
index c4b4d7c414d3c41a292ff9370d607a35707fbe7a..1d062ad191accf39740bb8570d8b9dbb64583555 100644
--- a/pixel.cpp
+++ b/pixel.cpp
@@ -18,7 +18,7 @@ void decrypt(int data);
 // void toAscii(char *c);
 
 
-void pixel(char key[1],
+void pixel(char key[3],
         ap_int<32> selector,
 		ap_int<32> position1,
 		ap_int<32> position2,