diff --git a/Makefile b/Makefile
index c8d03b7..4cec2c8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-VERSION := 9.1.0
+VERSION := 10.0.0
 MAJOR_VERSION := $(shell echo $(VERSION) | head -c 1)
 
 # installation directory (/usr/local by default)
diff --git a/src/cs50.h b/src/cs50.h
index b284ba2..0558f91 100644
--- a/src/cs50.h
+++ b/src/cs50.h
@@ -43,12 +43,7 @@
 #include <limits.h>
 #include <stdarg.h>
 #include <stdbool.h>
-#include <stdlib.h>
-
-/**
- * Our own type for bytes.
- */
-typedef unsigned char byte;
+#include <stddef.h>
 
 /**
  * Our own type for (pointers to) strings.