diff --git a/src/Command/AnalyserRunner.php b/src/Command/AnalyserRunner.php
index 633b11e3441..079b4d403bc 100644
--- a/src/Command/AnalyserRunner.php
+++ b/src/Command/AnalyserRunner.php
@@ -12,6 +12,7 @@
 use function array_filter;
 use function array_values;
 use function count;
+use function function_exists;
 use function is_file;
 
 class AnalyserRunner
@@ -58,7 +59,7 @@ public function runAnalyser(
 
 		if (
 			!$debug
-			&& $allowParallel
+			&& $allowParallel && function_exists('proc_open')
 			&& $mainScript !== null
 			&& $schedule->getNumberOfProcesses() > 0
 		) {