diff --git a/Helper/QuestionHelper.php b/Helper/QuestionHelper.php
index cb75ac914..f66d7bc55 100644
--- a/Helper/QuestionHelper.php
+++ b/Helper/QuestionHelper.php
@@ -495,19 +495,7 @@ private function isInteractiveInput($inputStream): bool
             return self::$stdinIsInteractive;
         }
 
-        if (\function_exists('stream_isatty')) {
-            return self::$stdinIsInteractive = @stream_isatty(fopen('php://stdin', 'r'));
-        }
-
-        if (\function_exists('posix_isatty')) {
-            return self::$stdinIsInteractive = @posix_isatty(fopen('php://stdin', 'r'));
-        }
-
-        if (!\function_exists('shell_exec')) {
-            return self::$stdinIsInteractive = true;
-        }
-
-        return self::$stdinIsInteractive = (bool) shell_exec('stty 2> '.('\\' === \DIRECTORY_SEPARATOR ? 'NUL' : '/dev/null'));
+        return self::$stdinIsInteractive = @stream_isatty(fopen('php://stdin', 'r'));
     }
 
     /**
diff --git a/Output/StreamOutput.php b/Output/StreamOutput.php
index aa3fe8b5d..84a7fa734 100644
--- a/Output/StreamOutput.php
+++ b/Output/StreamOutput.php
@@ -94,14 +94,13 @@ protected function hasColorSupport(): bool
             return false;
         }
 
-        if (!$this->isTty()) {
+        // Detect msysgit/mingw and assume this is a tty because detection
+        // does not work correctly, see https://github.com/composer/composer/issues/9690
+        if (!@stream_isatty($this->stream) && !\in_array(strtoupper((string) getenv('MSYSTEM')), ['MINGW32', 'MINGW64'], true)) {
             return false;
         }
 
-        if (\DIRECTORY_SEPARATOR === '\\'
-            && \function_exists('sapi_windows_vt100_support')
-            && @sapi_windows_vt100_support($this->stream)
-        ) {
+        if ('\\' === \DIRECTORY_SEPARATOR && @sapi_windows_vt100_support($this->stream)) {
             return true;
         }
 
@@ -113,43 +112,11 @@ protected function hasColorSupport(): bool
             return true;
         }
 
-        $term = (string) getenv('TERM');
-
-        if ('dumb' === $term) {
+        if ('dumb' === $term = (string) getenv('TERM')) {
             return false;
         }
 
         // See https://github.com/chalk/supports-color/blob/d4f413efaf8da045c5ab440ed418ef02dbb28bf1/index.js#L157
-        return 1 === @preg_match('/^((screen|xterm|vt100|vt220|putty|rxvt|ansi|cygwin|linux).*)|(.*-256(color)?(-bce)?)$/', $term);
-    }
-
-    /**
-     * Checks if the stream is a TTY, i.e; whether the output stream is connected to a terminal.
-     *
-     * Reference: Composer\Util\Platform::isTty
-     * https://github.com/composer/composer
-     */
-    private function isTty(): bool
-    {
-        // Detect msysgit/mingw and assume this is a tty because detection
-        // does not work correctly, see https://github.com/composer/composer/issues/9690
-        if (\in_array(strtoupper((string) getenv('MSYSTEM')), ['MINGW32', 'MINGW64'], true)) {
-            return true;
-        }
-
-        // Modern cross-platform function, includes the fstat fallback so if it is present we trust it
-        if (\function_exists('stream_isatty')) {
-            return stream_isatty($this->stream);
-        }
-
-        // Only trusting this if it is positive, otherwise prefer fstat fallback.
-        if (\function_exists('posix_isatty') && posix_isatty($this->stream)) {
-            return true;
-        }
-
-        $stat = @fstat($this->stream);
-
-        // Check if formatted mode is S_IFCHR
-        return $stat ? 0020000 === ($stat['mode'] & 0170000) : false;
+        return preg_match('/^((screen|xterm|vt100|vt220|putty|rxvt|ansi|cygwin|linux).*)|(.*-256(color)?(-bce)?)$/', $term);
     }
 }
diff --git a/Terminal.php b/Terminal.php
index 3eda0376b..9eb16aa74 100644
--- a/Terminal.php
+++ b/Terminal.php
@@ -140,7 +140,7 @@ private static function initDimensions(): void
                 // or [w, h] from "wxh"
                 self::$width = (int) $matches[1];
                 self::$height = isset($matches[4]) ? (int) $matches[4] : (int) $matches[2];
-            } elseif (!self::hasVt100Support() && self::hasSttyAvailable()) {
+            } elseif (!sapi_windows_vt100_support(fopen('php://stdout', 'w')) && self::hasSttyAvailable()) {
                 // only use stty on Windows if the terminal does not support vt100 (e.g. Windows 7 + git-bash)
                 // testing for stty in a Windows 10 vt100-enabled console will implicitly disable vt100 support on STDOUT
                 self::initDimensionsUsingStty();
@@ -154,14 +154,6 @@ private static function initDimensions(): void
         }
     }
 
-    /**
-     * Returns whether STDOUT has vt100 support (some Windows 10+ configurations).
-     */
-    private static function hasVt100Support(): bool
-    {
-        return \function_exists('sapi_windows_vt100_support') && sapi_windows_vt100_support(fopen('php://stdout', 'w'));
-    }
-
     /**
      * Initializes dimensions using the output of an stty columns line.
      */