diff --git a/src/userprog/syscall.c b/src/userprog/syscall.c
index 2926bbd..ddbbd39 100644
--- a/src/userprog/syscall.c
+++ b/src/userprog/syscall.c
@@ -34,7 +34,7 @@ static const syscall_arguments syscall_lookup[] = {
 
 /* The number of syscall functions (i.e, number of elements) within the
    syscall_lookup table. */
-static const int lookup_size
+static const int LOOKUP_SIZE
   = sizeof (syscall_lookup) / sizeof (syscall_arguments);
 
 void
@@ -51,7 +51,7 @@ syscall_handler (struct intr_frame *f)
   int syscall_number = *(int *) f->esp;
 
   /* Ensures the number corresponds to a system call that can be handled. */
-  if (syscall_number < 0 || syscall_number >= lookup_size)
+  if (syscall_number < 0 || syscall_number >= LOOKUP_SIZE)
     thread_exit ();
 
   syscall_arguments syscall = syscall_lookup[syscall_number];