1 files changed, 1 insertions, 1 deletions
diff --git a/strftime.c b/strftime.c
index 4451fe3c6b..a8a688608e 100644
--- a/strftime.c
+++ b/strftime.c
@@ -219,7 +219,7 @@ case_conv(char *s, ptrdiff_t i, int flags)
 static VALUE
 format_value(VALUE val, int base)
 {
-	if (!RB_TYPE_P(val, T_BIGNUM))
+	if (!RB_BIGNUM_TYPE_P(val))
 		val = rb_Integer(val);
 	return rb_big2str(val, base);
 }