Index: kernel/generic/src/printf/printf_core.c
===================================================================
--- kernel/generic/src/printf/printf_core.c	(revision d09f84e67ea1b8e6963a334fc5947e9c6441b7f9)
+++ kernel/generic/src/printf/printf_core.c	(revision 82bb9c121efbe640882ffd5dbdc9101eb995d0fa)
@@ -269,5 +269,5 @@
 
 	int retval;
-	size_t size = str_lsize(str, precision);
+	size_t size = str_wsize(str, precision);
 	if ((retval = printf_putnchars_utf8(str, size, ps)) < 0)
 		return -counter;
@@ -314,5 +314,5 @@
 
 	int retval;
-	size_t size = min(strw, precision) * sizeof(wchar_t);
+	size_t size = wstr_wlength(wstr, precision) * sizeof(wchar_t);
 	if ((retval = printf_putnchars_utf32(wstr, size, ps)) < 0)
 		return -counter;