diff --git a/src/corelib/global/qsimd.h b/src/corelib/global/qsimd.h
index 325faf123a..5fd34d0092 100644
--- a/src/corelib/global/qsimd.h
+++ b/src/corelib/global/qsimd.h
@@ -154,4 +154,7 @@
 #define QT_VECTORCALL
 #endif
 
+QT_BEGIN_NAMESPACE
+QT_END_NAMESPACE
+
 #endif // QSIMD_H