diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index e47f284a42..aab5625d00 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -365,7 +365,6 @@
 #        define Q_COMPILER_ATTRIBUTES
 #        define Q_COMPILER_AUTO_FUNCTION
 #        define Q_COMPILER_CLASS_ENUM
-#        define Q_COMPILER_CONSTEXPR
 #        define Q_COMPILER_DECLTYPE
 #        define Q_COMPILER_DEFAULT_MEMBERS
 #        define Q_COMPILER_DELETE_MEMBERS
diff --git a/src/corelib/thread/qbasicatomic.h b/src/corelib/thread/qbasicatomic.h
index 9804e60119..c9c95cf6ce 100644
--- a/src/corelib/thread/qbasicatomic.h
+++ b/src/corelib/thread/qbasicatomic.h
@@ -47,9 +47,9 @@
 #  include <QtCore/qatomic_bootstrap.h>
 
 // If C++11 atomics are supported, use them!
-// Note that constexpr support is sometimes disabled in QNX builds but its
-// library has <atomic>.
-#elif defined(Q_COMPILER_ATOMICS) && (defined(Q_COMPILER_CONSTEXPR) || defined(Q_OS_QNX))
+// Note that constexpr support is sometimes disabled in QNX or INTEGRITY builds,
+// but their libraries have <atomic>.
+#elif defined(Q_COMPILER_ATOMICS) && (defined(Q_COMPILER_CONSTEXPR) || defined(Q_OS_QNX) || defined(Q_OS_INTEGRITY))
 #  include <QtCore/qatomic_cxx11.h>
 
 // We only support one fallback: MSVC, because even on version 2015, it lacks full constexpr support