Index: src/OFMutableString.m
==================================================================
--- src/OFMutableString.m
+++ src/OFMutableString.m
@@ -63,15 +63,14 @@
 
 		return;
 	}
 
 	ulen = [self length];
-	ustr = [self allocMemoryForNItems: [self length]
-				 withSize: ulen];
+	ustr = [self allocMemoryForNItems: ulen
+				 withSize: sizeof(of_unichar_t)];
 
-	i = 0;
-	j = 0;
+	i = j = 0;
 	nlen = 0;
 
 	while (i < length) {
 		clen = of_string_utf8_to_unicode(string + i, length - i, &c);