diff --git a/kernel/threading.cc b/kernel/threading.cc
index 49fddaa7c..dcc044c89 100644
--- a/kernel/threading.cc
+++ b/kernel/threading.cc
@@ -3,6 +3,20 @@
 
 YOSYS_NAMESPACE_BEGIN
 
+static int init_max_threads()
+{
+	const char *v = getenv("YOSYS_MAX_THREADS");
+	if (v == nullptr)
+		return INT32_MAX;
+	return atoi(v);
+}
+
+static int get_max_threads()
+{
+	static int max_threads = init_max_threads();
+	return max_threads;
+}
+
 void DeferredLogs::flush()
 {
 	for (auto &m : logs)
@@ -12,10 +26,11 @@ void DeferredLogs::flush()
 			YOSYS_NAMESPACE_PREFIX log("%s", m.text.c_str());
 }
 
-int ThreadPool::pool_size(int reserved_cores, int max_threads)
+int ThreadPool::pool_size(int reserved_cores, int max_worker_threads)
 {
 #ifdef YOSYS_ENABLE_THREADS
-	int num_threads = std::min<int>(std::thread::hardware_concurrency() - reserved_cores, max_threads);
+	int available_threads = std::min<int>(std::thread::hardware_concurrency(), get_max_threads());
+	int num_threads = std::min(available_threads - reserved_cores, max_worker_threads);
         return std::max(0, num_threads);
 #else
         return 0;
diff --git a/kernel/threading.h b/kernel/threading.h
index c34abf850..b8cd62f87 100644
--- a/kernel/threading.h
+++ b/kernel/threading.h
@@ -127,9 +127,9 @@ class ThreadPool
 public:
 	// Computes the number of worker threads to use.
 	// `reserved_cores` cores are set aside for other threads (e.g. work on the main thread).
-	// `max_threads` --- don't return more workers than this.
+	// `max_worker_threads` --- don't return more workers than this.
 	// The result may be 0.
-	static int pool_size(int reserved_cores, int max_threads);
+	static int pool_size(int reserved_cores, int max_worker_threads);
 
 	// Create a pool of threads running the given closure (parameterized by thread number).
 	// `pool_size` must be the result of a `pool_size()` call.