diff --git a/Helper/QuestionHelper.php b/Helper/QuestionHelper.php
index f32813c6c..b40b13191 100644
--- a/Helper/QuestionHelper.php
+++ b/Helper/QuestionHelper.php
@@ -501,19 +501,7 @@ 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 a1cdb33cd..49928dd45 100644
--- a/Output/StreamOutput.php
+++ b/Output/StreamOutput.php
@@ -101,10 +101,7 @@ protected function hasColorSupport(): bool
             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;
         }
 
@@ -116,14 +113,12 @@ 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)?)$/', $term);
+        return preg_match('/^((screen|xterm|vt100|vt220|putty|rxvt|ansi|cygwin|linux).*)|(.*-256(color)?(-bce)?)$/', $term);
     }
 
     /**
@@ -140,19 +135,6 @@ private function isTty(): bool
             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 @stream_isatty($this->stream);
     }
 }