Index: uspace/lib/libc/include/ctype.h
===================================================================
--- uspace/lib/libc/include/ctype.h	(revision 0fdd6bbb06ebd929c2d9e4c5f604650f5f06ef82)
+++ uspace/lib/libc/include/ctype.h	(revision 3e53ab7b0eacdf72743712841abf0bf6d897b956)
@@ -80,5 +80,5 @@
 {
 	if (isupper(c))
-		return (c + ('a' - 'A' > 0 ? 'a' - 'A' : 'A' - 'a'));
+		return (c + ('a' - 'A'));
 	else
 		return c;
@@ -88,5 +88,5 @@
 {
 	if (islower(c))
-		return (c - ('a' - 'A' > 0 ? 'a' - 'A' : 'A' - 'a'));
+		return (c + ('A' - 'a'));
 	else
 		return c;