diff --git a/test/unit/stdlib/math/bigint.c3 b/test/unit/stdlib/math/bigint.c3
index 41b21f718..51eb40a6b 100644
--- a/test/unit/stdlib/math/bigint.c3
+++ b/test/unit/stdlib/math/bigint.c3
@@ -1,5 +1,20 @@
 module std::math::bigint @test;
 
+fn void test_init_with_u128()
+{
+	BigInt bi @noinit;
+	assert(!bi.init_with_u128(uint128.max).is_negative());
+}
+
+fn void init_with_array()
+{
+	BigInt bi @noinit;
+
+	assert(bi.init_with_array({0, 0, 0, 1}).equals(bigint::from_int(1)));
+
+	assert("100000000" == bi.init_with_array({1, 0}).to_string_with_radix(16, allocator::temp()));
+}
+
 fn void test_parse16()
 {
 	BigInt bi @noinit;