diff --git a/etc/openqa/workers.ini b/etc/openqa/workers.ini
index b1c631e5180..28685760ecc 100644
--- a/etc/openqa/workers.ini
+++ b/etc/openqa/workers.ini
@@ -76,7 +76,10 @@
 # Specifies the threshold to consider the load on the machine critical. If the
 # average load (over the last 15 minutes) exceeds the specified value the worker
 # will not accept new jobs (until the load decreases again).
-#CRITICAL_LOAD_AVG_THRESHOLD = 10
+# The default value is 40 to prevent system overload based on experiences with
+# system stability so far.
+# Set to 0 to disable.
+#CRITICAL_LOAD_AVG_THRESHOLD = 40
 
 # The section ids are the instance of the workers.
 # The key/value pairs will appear in vars.json
diff --git a/lib/OpenQA/Worker/Settings.pm b/lib/OpenQA/Worker/Settings.pm
index 74d3b37ee9c..fa0587509e1 100644
--- a/lib/OpenQA/Worker/Settings.pm
+++ b/lib/OpenQA/Worker/Settings.pm
@@ -65,6 +65,10 @@ sub new ($class, $instance_number = undef, $cli_options = {}) {
         }
     }
 
+    # Select sensible system CPU load15 threshold to prevent system overload
+    # based on experiences with system stability so far
+    $global_settings{CRITICAL_LOAD_AVG_THRESHOLD} //= 40;
+
     # set some environment variables
     # TODO: This should be sent to the scheduler to be included in the worker's table.
     if (defined $instance_number) {
diff --git a/t/24-worker-settings.t b/t/24-worker-settings.t
index 6646ba5c0d2..d7d300b4f89 100644
--- a/t/24-worker-settings.t
+++ b/t/24-worker-settings.t
@@ -20,6 +20,7 @@ my $settings = OpenQA::Worker::Settings->new;
 is_deeply(
     $settings->global_settings,
     {
+        CRITICAL_LOAD_AVG_THRESHOLD => 40,
         GLOBAL => 'setting',
         WORKER_HOSTNAME => '127.0.0.1',
         LOG_LEVEL => 'test',
@@ -82,6 +83,7 @@ subtest 'instance-specific settings' => sub {
     is_deeply(
         $settings1->global_settings,
         {
+            CRITICAL_LOAD_AVG_THRESHOLD => 40,
             GLOBAL => 'setting',
             WORKER_HOSTNAME => '127.0.0.1',
             WORKER_CLASS => 'qemu_i386,qemu_x86_64',
@@ -96,6 +98,7 @@ subtest 'instance-specific settings' => sub {
     is_deeply(
         $settings2->global_settings,
         {
+            CRITICAL_LOAD_AVG_THRESHOLD => 40,
             GLOBAL => 'setting',
             WORKER_HOSTNAME => '127.0.0.1',
             WORKER_CLASS => 'qemu_aarch64',