-(def-foreign-type string-pointer (* (* :char)))
-(def-foreign-type sqlite-row-pointer (* string-pointer))
+(def-foreign-type string-pointer (* (* :unsigned-char)))
+(def-foreign-type sqlite-row-pointer (* (* :unsigned-char)))
+
+(defvar +null-errmsg-pointer+ (make-null-pointer 'errmsg))
+(defvar +null-string-pointer-pointer+ (make-null-pointer 'string-pointer))
+