diff --git a/cubesatsim/cubesatsim.ino b/cubesatsim/cubesatsim.ino
index 9bf04cc4..1d8bd5c8 100644
--- a/cubesatsim/cubesatsim.ino
+++ b/cubesatsim/cubesatsim.ino
@@ -1574,7 +1574,7 @@ int upper_digit(int number) {
   return digit;
 }
 
-void print_string(*string)
+void print_string(char *string)
 {
   int count = 0;
   while ((count++ < 250) && (string[i] != NULL))