@@ -62,11 +62,11 @@
 		@try {
 			memcpy(name, "is", 2);
 			memcpy(name + 2, [key UTF8String], keyLength);
 			name[keyLength + 2] = '\0';
 
-			name[2] = toupper((unsigned char)name[2]);
+			name[2] = of_ascii_toupper(name[2]);
 
 			selector = sel_registerName(name);
 		} @finally {
 			free(name);
 		}
@@ -144,11 +144,11 @@
 	@try {
 		memcpy(name, "set", 3);
 		memcpy(name + 3, [key UTF8String], keyLength);
 		memcpy(name + keyLength + 3, ":", 2);
 
-		name[3] = toupper((unsigned char)name[3]);
+		name[3] = of_ascii_toupper(name[3]);
 
 		selector = sel_registerName(name);
 	} @finally {
 		free(name);
 	}