diff --git a/Output/StreamOutput.php b/Output/StreamOutput.php
index 218bc9ef2..ca90096a4 100644
--- a/Output/StreamOutput.php
+++ b/Output/StreamOutput.php
@@ -93,7 +93,7 @@ protected function doWrite(string $message, bool $newline)
     protected function hasColorSupport(): bool
     {
         // Follow https://no-color.org/
-        if (isset($_SERVER['NO_COLOR']) || false !== getenv('NO_COLOR')) {
+        if ('' !== ($_SERVER['NO_COLOR'] ?? getenv('NO_COLOR') ?: '')) {
             return false;
         }
 
diff --git a/Tests/ApplicationTest.php b/Tests/ApplicationTest.php
index d8e1ae8b9..ac1d47245 100644
--- a/Tests/ApplicationTest.php
+++ b/Tests/ApplicationTest.php
@@ -71,12 +71,10 @@ protected function tearDown(): void
 
         if (\function_exists('pcntl_signal')) {
             // We reset all signals to their default value to avoid side effects
-            for ($i = 1; $i <= 15; ++$i) {
-                if (9 === $i) {
-                    continue;
-                }
-                pcntl_signal($i, \SIG_DFL);
-            }
+            pcntl_signal(\SIGINT, \SIG_DFL);
+            pcntl_signal(\SIGTERM, \SIG_DFL);
+            pcntl_signal(\SIGUSR1, \SIG_DFL);
+            pcntl_signal(\SIGUSR2, \SIG_DFL);
         }
     }
 
diff --git a/Tests/ConsoleEventsTest.php b/Tests/ConsoleEventsTest.php
index 93c228aa4..9c04d2706 100644
--- a/Tests/ConsoleEventsTest.php
+++ b/Tests/ConsoleEventsTest.php
@@ -35,12 +35,10 @@ protected function tearDown(): void
         if (\function_exists('pcntl_signal')) {
             pcntl_async_signals(false);
             // We reset all signals to their default value to avoid side effects
-            for ($i = 1; $i <= 15; ++$i) {
-                if (9 === $i) {
-                    continue;
-                }
-                pcntl_signal($i, \SIG_DFL);
-            }
+            pcntl_signal(\SIGINT, \SIG_DFL);
+            pcntl_signal(\SIGTERM, \SIG_DFL);
+            pcntl_signal(\SIGUSR1, \SIG_DFL);
+            pcntl_signal(\SIGUSR2, \SIG_DFL);
         }
     }
 
diff --git a/Tests/SignalRegistry/SignalRegistryTest.php b/Tests/SignalRegistry/SignalRegistryTest.php
index 4cb435416..f997f7c1d 100644
--- a/Tests/SignalRegistry/SignalRegistryTest.php
+++ b/Tests/SignalRegistry/SignalRegistryTest.php
@@ -23,12 +23,10 @@ protected function tearDown(): void
     {
         pcntl_async_signals(false);
         // We reset all signals to their default value to avoid side effects
-        for ($i = 1; $i <= 15; ++$i) {
-            if (9 === $i) {
-                continue;
-            }
-            pcntl_signal($i, \SIG_DFL);
-        }
+        pcntl_signal(\SIGINT, \SIG_DFL);
+        pcntl_signal(\SIGTERM, \SIG_DFL);
+        pcntl_signal(\SIGUSR1, \SIG_DFL);
+        pcntl_signal(\SIGUSR2, \SIG_DFL);
     }
 
     public function testOneCallbackForASignalSignalIsHandled()