diff --git a/tests/auto/corelib/global/qglobal/CMakeLists.txt b/tests/auto/corelib/global/qglobal/CMakeLists.txt
index 5a0877663b..527e218aba 100644
--- a/tests/auto/corelib/global/qglobal/CMakeLists.txt
+++ b/tests/auto/corelib/global/qglobal/CMakeLists.txt
@@ -19,5 +19,17 @@ qt_internal_add_test(tst_qglobal
         tst_qglobal.cpp # undef QT_NO_FOREACH
 )
 
+# check stuff (esp. qtypes.h) works in -ansi mode
+qt_internal_add_test(tst_qglobal_strict
+    SOURCES
+        qglobal.c
+        tst_qglobal.cpp
+    DEFINES
+        tst_QGlobal=tst_QGlobal_strict
+    NO_PCH_SOURCES
+        tst_qglobal.cpp # undef QT_NO_FOREACH
+)
+_qt_internal_apply_strict_cpp(tst_qglobal_strict)
+
 ## Scopes:
 #####################################################################
diff --git a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
index 954eab6a43..e67f991fae 100644
--- a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
+++ b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
@@ -544,13 +544,25 @@ void tst_QGlobal::integerForSize()
 void tst_QGlobal::int128Literals()
 {
 #ifdef QT_SUPPORTS_INT128
+# if defined(__GLIBCXX__) && defined(__STRICT_ANSI__) && \
+    (_GLIBCXX_RELEASE < 10 || \
+    _GLIBCXX_RELEASE == 10 && __GLIBCXX__ < 20201112L /*gcc commit 8eb9a45e87bdb81cb44948c651edee846c622a0f*/)
+    // -ansi/-std=c++NN instead of gnu++NN
+    // breaks <type_traits> on libstdc++ <= 10.2; fixed in 10.3+
+#   define QTBUG_119901_MAYBE_FAIL QEXPECT_FAIL("", "QTBUG-119901", Continue)
+# else
+#   define QTBUG_119901_MAYBE_FAIL do {} while (false)
+# endif
 #define COMPARE_EQ(lhs, rhs, Expected128) do { \
         constexpr auto lhs_ = lhs; \
         static_assert(std::is_same_v<std::remove_cv_t<decltype(lhs_)>, Expected128>); \
         QCOMPARE_EQ(lhs_, rhs); \
     } while (0)
+    QTBUG_119901_MAYBE_FAIL;
     COMPARE_EQ(Q_INT128_MIN, std::numeric_limits<qint128>::min(), qint128);
+    QTBUG_119901_MAYBE_FAIL;
     COMPARE_EQ(Q_INT128_MAX, std::numeric_limits<qint128>::max(), qint128);
+    QTBUG_119901_MAYBE_FAIL;
     COMPARE_EQ(Q_UINT128_MAX, std::numeric_limits<quint128>::max(), quint128);
     QCOMPARE_EQ(tst_qint128_min(), Q_INT128_MIN);
     QCOMPARE_EQ(tst_qint128_max(), Q_INT128_MAX);
@@ -603,6 +615,7 @@ void tst_QGlobal::int128Literals()
             // the literal, but called on the result of the literal.
             constexpr auto i = Q_INT128_C(-170141183460469231731687303715884105727); // 128-bit MIN + 1
             static_assert(std::is_same_v<decltype(i), const qint128>);
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(i, std::numeric_limits<qint128>::min() + 1);
         }
         {
@@ -610,7 +623,9 @@ void tst_QGlobal::int128Literals()
             constexpr auto u = Q_UINT128_C(340282366920938463463374607431768211455); // UMAX
             static_assert(std::is_same_v<decltype(i), const qint128>);
             static_assert(std::is_same_v<decltype(u), const quint128>);
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(i, std::numeric_limits<qint128>::max());
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(u, std::numeric_limits<quint128>::max());
             QCOMPARE_EQ(u, Q_UINT128_C(-1));
         }
@@ -630,7 +645,9 @@ void tst_QGlobal::int128Literals()
             constexpr auto u = Q_UINT128_C(0b1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111'1111);
             static_assert(std::is_same_v<decltype(i), const qint128>);
             static_assert(std::is_same_v<decltype(u), const quint128>);
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(i, std::numeric_limits<qint128>::max());
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(u, std::numeric_limits<quint128>::max());
             QCOMPARE_EQ(u, Q_UINT128_C(-0b1));
         }
@@ -654,7 +671,9 @@ void tst_QGlobal::int128Literals()
             constexpr auto u = Q_UINT128_C(0377'7777'7777'7777'7777'7777'7777'7777'7777'7777'7777);
             static_assert(std::is_same_v<decltype(i), const qint128>);
             static_assert(std::is_same_v<decltype(u), const quint128>);
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(i, std::numeric_limits<qint128>::max());
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(u, std::numeric_limits<quint128>::max());
             QCOMPARE_EQ(u, Q_UINT128_C(-01));
         }
@@ -678,12 +697,15 @@ void tst_QGlobal::int128Literals()
             constexpr auto u = Q_UINT128_C(0xFFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF'FFFF);
             static_assert(std::is_same_v<decltype(i), const qint128>);
             static_assert(std::is_same_v<decltype(u), const quint128>);
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(i, std::numeric_limits<qint128>::max());
+            QTBUG_119901_MAYBE_FAIL;
             QCOMPARE_EQ(u, std::numeric_limits<quint128>::max());
             QCOMPARE_EQ(Q_UINT128_C(-1), u);
         }
     #undef CHECK
     }
+#undef QTBUG_119901_MAYBE_FAIL
 #undef COMPARE_EQ
 #else
     QSKIP("This test requires 128-bit integer support enabled in the compiler.");