diff --git a/src/corelib/io/qloggingregistry.cpp b/src/corelib/io/qloggingregistry.cpp
index 47fb1fb6b8..9a5c923323 100644
--- a/src/corelib/io/qloggingregistry.cpp
+++ b/src/corelib/io/qloggingregistry.cpp
@@ -255,6 +255,7 @@ void QLoggingSettingsParser::parseNextLine(QStringRef line)
 QLoggingRegistry::QLoggingRegistry()
     : categoryFilter(defaultCategoryFilter)
 {
+    init();
 }
 
 static bool qtLoggingDebug()
diff --git a/src/corelib/io/qloggingregistry_p.h b/src/corelib/io/qloggingregistry_p.h
index 69fc6ea4ec..768f3b4a91 100644
--- a/src/corelib/io/qloggingregistry_p.h
+++ b/src/corelib/io/qloggingregistry_p.h
@@ -113,8 +113,6 @@ class Q_AUTOTEST_EXPORT QLoggingRegistry
 public:
     QLoggingRegistry();
 
-    void init();
-
     void registerCategory(QLoggingCategory *category, QtMsgType enableForLevel);
     void unregisterCategory(QLoggingCategory *category);
 
@@ -126,6 +124,7 @@ public:
     static QLoggingRegistry *instance();
 
 private:
+    void init();
     void updateRules();
 
     static void defaultCategoryFilter(QLoggingCategory *category);
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index e4b1562b8b..0216baa6c3 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -771,8 +771,6 @@ void QCoreApplicationPrivate::init()
     if (!coreappdata()->applicationVersionSet)
         coreappdata()->applicationVersion = appVersion();
 
-    QLoggingRegistry::instance()->init();
-
 #if QT_CONFIG(library)
     // Reset the lib paths, so that they will be recomputed, taking the availability of argv[0]
     // into account. If necessary, recompute right away and replay the manual changes on top of the
diff --git a/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp b/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
index 0a74dc64c0..c697cb2203 100644
--- a/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
+++ b/tests/auto/corelib/io/qloggingregistry/tst_qloggingregistry.cpp
@@ -197,9 +197,23 @@ private slots:
         // Check whether QT_LOGGING_CONF is picked up from environment
         //
 
-        qputenv("QT_LOGGING_CONF", QFINDTESTDATA("qtlogging.ini").toLocal8Bit());
+        Q_ASSERT(!qApp);
+
+        qputenv("QT_LOGGING_RULES", "qt.foo.bar=true");
 
         QLoggingRegistry registry;
+        QCOMPARE(registry.apiRules.size(), 0);
+        QCOMPARE(registry.configRules.size(), 0);
+        QCOMPARE(registry.envRules.size(), 1);
+        QCOMPARE(registry.rules.size(), 1);
+
+        QLoggingCategory qtEnabledByLoggingRule("qt.foo.bar");
+        QCOMPARE(qtEnabledByLoggingRule.isDebugEnabled(), true);
+        QLoggingCategory qtDisabledByDefault("qt.foo.baz");
+        QCOMPARE(qtDisabledByDefault.isDebugEnabled(), false);
+
+        qunsetenv("QT_LOGGING_RULES");
+        qputenv("QT_LOGGING_CONF", QFINDTESTDATA("qtlogging.ini").toLocal8Bit());
         registry.init();
 
         QCOMPARE(registry.apiRules.size(), 0);
@@ -304,6 +318,6 @@ private slots:
     }
 };
 
-QTEST_MAIN(tst_QLoggingRegistry)
+QTEST_APPLESS_MAIN(tst_QLoggingRegistry)
 
 #include "tst_qloggingregistry.moc"