diff --git a/src/CLI/Console.php b/src/CLI/Console.php
index 4b8af2a..43057bc 100644
--- a/src/CLI/Console.php
+++ b/src/CLI/Console.php
@@ -131,7 +131,7 @@ public static function exit(int $status = 0): void
      * @param  int  $timeout
      * @return int
      */
-    public static function execute(string $cmd, string $stdin, string &$stdout, string &$stderr, int $timeout = -1, callable $onProgress = null): int
+    public static function execute(string $cmd, string $stdin, string &$output, int $timeout = -1, callable $onProgress = null): int
     {
         $cmd = '( '.$cmd.' ) 3>/dev/null ; echo $? >&3';
 
@@ -142,8 +142,7 @@ public static function execute(string $cmd, string $stdin, string &$stdout, stri
             $pipes
         );
         $start = \time();
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $status = '';
 
         if (\is_resource($process)) {
@@ -159,12 +158,19 @@ public static function execute(string $cmd, string $stdin, string &$stdout, stri
         while (\is_resource($process)) {
             $stdoutContents = \stream_get_contents($pipes[1]) ?: '';
             $stderrContents = \stream_get_contents($pipes[2]) ?: '';
-            if (isset($onProgress) && (! empty($stdoutContents) || ! empty($stderrContents))) {
-                $onProgress($stdoutContents, $stderrContents, $process);
+
+            $outputContents = $stdoutContents ?? '';
+
+            if (! empty($stderrContents)) {
+                $separator = empty($outputContents) ? '' : "\n";
+                $outputContents .= $separator.$stderrContents;
+            }
+
+            if (isset($onProgress) && (! empty($outputContents))) {
+                $onProgress($outputContents, $process);
             }
 
-            $stdout .= $stdoutContents;
-            $stderr .= $stderrContents;
+            $output .= $outputContents;
             $status .= \stream_get_contents($pipes[3]);
 
             if ($timeout > 0 && \time() - $start > $timeout) {
diff --git a/tests/CLI/ConsoleTest.php b/tests/CLI/ConsoleTest.php
index d80582e..e37ec63 100755
--- a/tests/CLI/ConsoleTest.php
+++ b/tests/CLI/ConsoleTest.php
@@ -28,99 +28,80 @@ public function testLogs()
 
     public function testExecuteBasic()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('php -r "echo \'hello world\';"', $stdin, $stdout, $stderr, 10);
+        $code = Console::execute('php -r "echo \'hello world\';"', $stdin, $output, 10);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('hello world', $stdout);
+        $this->assertEquals('hello world', $output);
         $this->assertEquals(0, $code);
     }
 
     public function testExecuteStream()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
 
-        $stdoutStream = '';
-        $stderrStream = '';
-        $code = Console::execute('printf 1 && sleep 1 && printf 2 && sleep 1 && printf 3 && sleep 1 && printf 4 && sleep 1 && printf 5', $stdin, $stdout, $stderr, 10, function ($stdout, $stderr) use (&$stdoutStream, &$stderrStream) {
-            $stdoutStream .= $stdout;
-            $stderrStream .= $stderr;
+        $outputStream = '';
+        $code = Console::execute('printf 1 && sleep 1 && printf 2 && sleep 1 && printf 3 && sleep 1 && printf 4 && sleep 1 && printf 5', $stdin, $output, 10, function ($output) use (&$outputStream) {
+            $outputStream .= $output;
         });
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('12345', $stdout);
-        $this->assertEquals('', $stderrStream);
-        $this->assertEquals('12345', $stdoutStream);
+        $this->assertEquals('12345', $output);
+        $this->assertEquals('12345', $outputStream);
         $this->assertEquals(0, $code);
     }
 
     public function testExecuteStdOut()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('>&1 echo "success"', $stdin, $stdout, $stderr, 3);
+        $code = Console::execute('>&1 echo "success"', $stdin, $output, 3);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals("success\n", $stdout);
+        $this->assertEquals("success\n", $output);
         $this->assertEquals(0, $code);
     }
 
     public function testExecuteStdErr()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('>&2 echo "error"', $stdin, $stdout, $stderr, 3);
+        $code = Console::execute('>&2 echo "error"', $stdin, $output, 3);
 
-        $this->assertEquals("error\n", $stderr);
-        $this->assertEquals('', $stdout);
+        $this->assertEquals("error\n", $output);
         $this->assertEquals(0, $code);
     }
 
     public function testExecuteExitCode()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('php -r "echo \'hello world\'; exit(2);"', $stdin, $stdout, $stderr, 10);
+        $code = Console::execute('php -r "echo \'hello world\'; exit(2);"', $stdin, $output, 10);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('hello world', $stdout);
+        $this->assertEquals('hello world', $output);
         $this->assertEquals(2, $code);
 
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('php -r "echo \'hello world\'; exit(100);"', $stdin, $stdout, $stderr, 10);
+        $code = Console::execute('php -r "echo \'hello world\'; exit(100);"', $stdin, $output, 10);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('hello world', $stdout);
+        $this->assertEquals('hello world', $output);
         $this->assertEquals(100, $code);
     }
 
     public function testExecuteTimeout()
     {
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('php -r "sleep(1); echo \'hello world\'; exit(0);"', $stdin, $stdout, $stderr, 3);
+        $code = Console::execute('php -r "sleep(1); echo \'hello world\'; exit(0);"', $stdin, $output, 3);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('hello world', $stdout);
+        $this->assertEquals('hello world', $output);
         $this->assertEquals(0, $code);
 
-        $stdout = '';
-        $stderr = '';
+        $output = '';
         $stdin = '';
-        $code = Console::execute('php -r "sleep(4); echo \'hello world\'; exit(0);"', $stdin, $stdout, $stderr, 3);
+        $code = Console::execute('php -r "sleep(4); echo \'hello world\'; exit(0);"', $stdin, $output, 3);
 
-        $this->assertEquals('', $stderr);
-        $this->assertEquals('', $stdout);
+        $this->assertEquals('', $output);
         $this->assertEquals(1, $code);
     }
 
@@ -128,13 +109,11 @@ public function testLoop()
     {
         $file = __DIR__.'/../resources/loop.php';
         $stdin = '';
-        $stdout = '';
-        $stderr = '';
-        $code = Console::execute('php '.$file, $stdin, $stdout, $stderr, 30);
+        $output = '';
+        $code = Console::execute('php '.$file, $stdin, $output, 30);
 
-        $this->assertEquals('', $stderr);
-        $this->assertGreaterThan(30, count(explode("\n", $stdout)));
-        $this->assertLessThan(50, count(explode("\n", $stdout)));
+        $this->assertGreaterThan(30, count(explode("\n", $output)));
+        $this->assertLessThan(50, count(explode("\n", $output)));
         $this->assertEquals(1, $code);
     }
 }