diff --git a/src/gmio_support/qt_stream.cpp b/src/gmio_support/qt_stream.cpp
index d2167eb..3798348 100644
--- a/src/gmio_support/qt_stream.cpp
+++ b/src/gmio_support/qt_stream.cpp
@@ -20,6 +20,8 @@
 #include <QtCore/QFile>
 #include <QtCore/QIODevice>
 
+QT_USE_NAMESPACE
+
 static gmio_bool_t gmio_stream_qiodevice_at_end(void* cookie)
 {
   return static_cast<QIODevice*>(cookie)->atEnd();
diff --git a/src/gmio_support/qt_stream.h b/src/gmio_support/qt_stream.h
index f779d97..83db31c 100644
--- a/src/gmio_support/qt_stream.h
+++ b/src/gmio_support/qt_stream.h
@@ -21,11 +21,16 @@
 #define GMIO_SUPPORT_QT_STREAM_H
 
 #include "support_global.h"
+#include <QtCore/QtGlobal>
+
 struct gmio_stream;
+QT_BEGIN_NAMESPACE
 class QIODevice;
+QT_END_NAMESPACE
 
 /*! Configures \p stream for \c QIODevice* (cookie will hold \p device) */
 GMIO_LIBSUPPORT_EXPORT
-void gmio_stream_set_qiodevice(struct gmio_stream* stream, QIODevice* device);
+void gmio_stream_set_qiodevice(
+        struct gmio_stream* stream, QT_PREPEND_NAMESPACE(QIODevice)* device);
 
 #endif /* GMIO_SUPPORT_QT_STREAM_H */