diff -Naur qtbase-opensource-src-5.6.1.orig/src/corelib/plugin/qfactoryloader.cpp qtbase-opensource-src-5.6.1/src/corelib/plugin/qfactoryloader.cpp
--- qtbase-opensource-src-5.6.1.orig/src/corelib/plugin/qfactoryloader.cpp	2016-10-31 16:51:05.058042123 +0100
+++ qtbase-opensource-src-5.6.1/src/corelib/plugin/qfactoryloader.cpp	2016-10-31 16:52:50.488044482 +0100
@@ -208,10 +208,12 @@
                     ++keyUsageCount;
                 }
             }
-            if (keyUsageCount || keys.isEmpty())
+            if (keyUsageCount || keys.isEmpty()) {
+	    	library->setLoadHints(QLibrary::PreventUnloadHint); // once loaded, don't unload
                 d->libraryList += library;
-            else
+            } else {
                 library->release();
+	    }
         }
     }
 #else
diff -Naur qtbase-opensource-src-5.6.1.orig/src/corelib/plugin/qpluginloader.cpp qtbase-opensource-src-5.6.1/src/corelib/plugin/qpluginloader.cpp
--- qtbase-opensource-src-5.6.1.orig/src/corelib/plugin/qpluginloader.cpp	2016-10-31 16:51:05.057042123 +0100
+++ qtbase-opensource-src-5.6.1/src/corelib/plugin/qpluginloader.cpp	2016-10-31 16:54:49.756047150 +0100
@@ -148,6 +148,7 @@
     : QObject(parent), d(0), did_load(false)
 {
     setFileName(fileName);
+    setLoadHints(QLibrary::PreventUnloadHint);
 }
 
 /*!
@@ -342,7 +343,7 @@
 void QPluginLoader::setFileName(const QString &fileName)
 {
 #if defined(QT_SHARED)
-    QLibrary::LoadHints lh;
+    QLibrary::LoadHints lh = QLibrary::PreventUnloadHint;
     if (d) {
         lh = d->loadHints();
         d->release();
@@ -391,7 +392,7 @@
     \brief Give the load() function some hints on how it should behave.
 
     You can give hints on how the symbols in the plugin are
-    resolved. By default, none of the hints are set.
+    resolved. By default since Qt 5.7, QLibrary::PreventUnloadHint is set.
 
     See the documentation of QLibrary::loadHints for a complete
     description of how this property works.