Index: register.h
===================================================================
--- register.h	(revision 51)
+++ register.h	(revision 52)
@@ -22,7 +22,7 @@
 Mostly used internally.
 **/
 
-extern char raydium_register_name_isvalid (char *name);
+extern signed char raydium_register_name_isvalid (char *name);
 /**
 Tests ##name##, and returns his viability as a boolean.
 Accepted intervals for variables and functions: [a-z], [A-Z] and '_'