diff --git a/libgnucash/engine/test/gtest-gnc-int128.cpp b/libgnucash/engine/test/gtest-gnc-int128.cpp
index 23c2b27053..4f28bdd262 100644
--- a/libgnucash/engine/test/gtest-gnc-int128.cpp
+++ b/libgnucash/engine/test/gtest-gnc-int128.cpp
@@ -192,33 +192,33 @@ TEST(GncInt128_functions, test_int_functions)
         });
 
     GncInt128 value2 (UINT64_C(0), uarg);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value2), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value2), std::overflow_error);
     EXPECT_EQ (uarg, static_cast<uint64_t>(value2));
 
     GncInt128 value3 (UINT64_C(0), uarg, GncInt128::neg);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value3), std::underflow_error);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value3), std::underflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value3), std::underflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value3), std::underflow_error);
 
     GncInt128 value4 (UINT64_C(0), uarg, GncInt128::overflow);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value4), std::overflow_error);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value4), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value4), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value4), std::overflow_error);
 
     GncInt128 value5 (UINT64_C(0), uarg, GncInt128::NaN);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value5), std::overflow_error);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value5), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value5), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value5), std::overflow_error);
 
     GncInt128 value6 (INT64_C(1), arg);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value6), std::overflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value6), std::overflow_error);
     EXPECT_EQ (arg + (UINT64_C(0x1) << 63), static_cast<uint64_t>(value6));
 
     GncInt128 value7 (INT64_C(-1), arg);
     EXPECT_EQ (-static_cast<int64_t>((UINT64_C(0x1) << 63) - arg),
                static_cast<int64_t>(value7));
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value7), std::underflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value7), std::underflow_error);
 
     GncInt128 value8 (INT64_C(0), narg);
     EXPECT_EQ (narg, static_cast<int64_t>(value8));
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value8), std::underflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value8), std::underflow_error);
 
     GncInt128 value9 (INT64_C(1), narg);
     EXPECT_EQ (static_cast<int64_t>((UINT64_C(0x1) << 63) + narg),
@@ -226,8 +226,8 @@ TEST(GncInt128_functions, test_int_functions)
     EXPECT_EQ ((UINT64_C(0x1) << 63) + narg, static_cast<uint64_t>(value9));
 
     GncInt128 value10 (INT64_C(-2), arg);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<int64_t>(value10), std::underflow_error);
-    EXPECT_THROW (auto v GTEST_ATTRIBUTE_UNUSED_ = static_cast<uint64_t>(value10),
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<int64_t>(value10), std::underflow_error);
+    EXPECT_THROW (auto v [[maybe_unused]] = static_cast<uint64_t>(value10),
                   std::underflow_error);
 
 }