diff --git a/autotests/testlog.cpp b/autotests/testlog.cpp
--- a/autotests/testlog.cpp
+++ b/autotests/testlog.cpp
@@ -55,6 +55,7 @@
 void TestLog::initTestCase()
 {
 
+    qputenv(KSCREEN_LOGGING, QByteArray("true"));
 }
 
 void TestLog::cleanupTestCase()
@@ -85,6 +86,13 @@
     qunsetenv(KSCREEN_LOGGING);
 
     log = Log::instance();
+    QCOMPARE(log->enabled(), false);
+    QCOMPARE(log->logFile(), QString());
+
+    delete log;
+    qputenv(KSCREEN_LOGGING, QByteArray("truE"));
+
+    log = Log::instance();
     QCOMPARE(log->enabled(), true);
     QCOMPARE(log->logFile(), m_defaultLogFile);
 
diff --git a/src/log.cpp b/src/log.cpp
--- a/src/log.cpp
+++ b/src/log.cpp
@@ -57,7 +57,7 @@
 {
   public:
       QString context;
-      bool enabled = true;
+      bool enabled = false;
       QString logFile;
 };
 
@@ -68,11 +68,13 @@
 
     if (qEnvironmentVariableIsSet(logging_env)) {
         const QString logging_env_value = qgetenv(logging_env).constData();
-        if (logging_env_value == QStringLiteral("0") || logging_env_value.toLower() == QStringLiteral("false")) {
-            d->enabled = false;
-            return;
+        if (logging_env_value != QStringLiteral("0") && logging_env_value.toLower() != QStringLiteral("false")) {
+            d->enabled = true;
         }
     }
+    if (!d->enabled) {
+         return;
+    }
     d->logFile = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation) + "/kscreen/kscreen.log";
 
     QLoggingCategory::setFilterRules("kscreen.*=true");