diff --git a/repos/libports/src/lib/pthread/thread.cc b/repos/libports/src/lib/pthread/thread.cc
index 2bda839fb..c2de95200 100644
--- a/repos/libports/src/lib/pthread/thread.cc
+++ b/repos/libports/src/lib/pthread/thread.cc
@@ -214,6 +214,21 @@ extern "C" {
 	}
 
 
+	int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
+	{
+		if (!attr || !*attr)
+			return EINVAL;
+
+		if (stacksize > (Thread::stack_virtual_size() - 4 * 4096) ||
+		    stacksize < 4096)
+			return EINVAL;
+
+		(*attr)->stack_size = Genode::align_addr(stacksize, 12);
+
+		return 0;
+	}
+
+
 	int pthread_attr_getstack(const pthread_attr_t *attr,
 	                          void **stackaddr,
 	                          ::size_t *stacksize)
diff --git a/repos/libports/src/lib/pthread/thread.h b/repos/libports/src/lib/pthread/thread.h
index 5be7c5806..db1cd9adb 100644
--- a/repos/libports/src/lib/pthread/thread.h
+++ b/repos/libports/src/lib/pthread/thread.h
@@ -48,8 +48,9 @@ extern "C" {
 	struct pthread_attr
 	{
 		pthread_t pthread;
+		size_t stack_size;
 
-		pthread_attr() : pthread(0) { }
+		pthread_attr() : pthread(0), stack_size(0) { }
 	};
 
 
diff --git a/repos/libports/src/lib/pthread/thread_create.cc b/repos/libports/src/lib/pthread/thread_create.cc
index 3db7f0fdd..7daf42574 100644
--- a/repos/libports/src/lib/pthread/thread_create.cc
+++ b/repos/libports/src/lib/pthread/thread_create.cc
@@ -30,8 +30,11 @@ extern "C"
 		/* cleanup threads which tried to self-destruct */
 		pthread_cleanup();
 
+		size_t const stack_size = (attr && *attr && (*attr)->stack_size)
+		                        ? (*attr)->stack_size : STACK_SIZE;
+
 		pthread_t thread_obj = new pthread(attr ? *attr : 0, start_routine,
-		                           arg, STACK_SIZE, "pthread", nullptr,
+		                           arg, stack_size, "pthread", nullptr,
 		                           Genode::Affinity::Location());
 
 		if (!thread_obj)