1 files changed, 1 insertions, 1 deletions
diff --git a/utf8.c b/utf8.c
index 0eafd76127..5c6f2715f3 100644
--- a/utf8.c
+++ b/utf8.c
@@ -875,7 +875,7 @@ Perl_utf16_to_utf8(pTHX_ U8* p, U8* d, I32 bytelen, I32 *newlen)
     }
 
     if (bytelen & 1)
-	Perl_croak(aTHX_ "panic: utf16_to_utf8: odd bytelen %d", bytelen);
+	Perl_croak(aTHX_ "panic: utf16_to_utf8: odd bytelen %"UVf, (UV)bytelen);
 
     pend = p + bytelen;