diff --git a/modules/mol/base/tests/test_chain.cc b/modules/mol/base/tests/test_chain.cc
index 4c2127670e1a65b67b0230a8a629809462e8712a..2154bdeab94555e73c89892847e6f9cac1759af4 100644
--- a/modules/mol/base/tests/test_chain.cc
+++ b/modules/mol/base/tests/test_chain.cc
@@ -327,7 +327,7 @@ BOOST_AUTO_TEST_CASE(chain_type)
    BOOST_CHECK(!ch1.IsPolynucleotide());
    e.SetChainType(ch1, CHAINTYPE_OLIGOSACCHARIDE);
    BOOST_CHECK(ch1.GetType() == CHAINTYPE_OLIGOSACCHARIDE);
-   BOOST_CHECK(!ch1.IsPolymer());
+   BOOST_CHECK(ch1.IsPolymer());
    BOOST_CHECK(!ch1.IsPolysaccharide());
    BOOST_CHECK(!ch1.IsPolypeptide());
    BOOST_CHECK(!ch1.IsPolynucleotide());