diff --git a/apps/openmw_test_suite/esm/test_fixed_string.cpp b/apps/openmw_test_suite/esm/test_fixed_string.cpp
index bd598cc932..b59f19e7bb 100644
--- a/apps/openmw_test_suite/esm/test_fixed_string.cpp
+++ b/apps/openmw_test_suite/esm/test_fixed_string.cpp
@@ -105,3 +105,46 @@ TEST(EsmFixedString, is_pod)
      ASSERT_TRUE(std::is_pod<ESM::NAME32>::value);
      ASSERT_TRUE(std::is_pod<ESM::NAME64>::value);
 }
+
+TEST(EsmFixedString, assign_should_zero_untouched_bytes_for_4)
+{
+    ESM::NAME value;
+    value = static_cast<uint32_t>(0xFFFFFFFFu);
+    value.assign(std::string(1, 'a'));
+    EXPECT_EQ(value, static_cast<uint32_t>('a')) << value.toInt();
+}
+
+TEST(EsmFixedString, assign_should_only_truncate_for_4)
+{
+    ESM::NAME value;
+    value.assign(std::string(5, 'a'));
+    EXPECT_EQ(value, std::string(4, 'a'));
+}
+
+TEST(EsmFixedString, assign_should_truncate_and_set_last_element_to_zero)
+{
+    ESM::FIXED_STRING<17> value;
+    value.assign(std::string(20, 'a'));
+    EXPECT_EQ(value, std::string(16, 'a'));
+}
+
+TEST(EsmFixedString, assign_should_truncate_and_set_last_element_to_zero_for_32)
+{
+    ESM::NAME32 value;
+    value.assign(std::string(33, 'a'));
+    EXPECT_EQ(value, std::string(31, 'a'));
+}
+
+TEST(EsmFixedString, assign_should_truncate_and_set_last_element_to_zero_for_64)
+{
+    ESM::NAME64 value;
+    value.assign(std::string(65, 'a'));
+    EXPECT_EQ(value, std::string(63, 'a'));
+}
+
+TEST(EsmFixedString, assignment_operator_is_supported_for_uint32)
+{
+    ESM::NAME value;
+    value = static_cast<uint32_t>(0xFEDCBA98u);
+    EXPECT_EQ(value, static_cast<uint32_t>(0xFEDCBA98u)) << value.toInt();
+}