diff --git a/lib/pls/include/pls/pls.h b/lib/pls/include/pls/pls.h
index b766dfe..c38f5d6 100644
--- a/lib/pls/include/pls/pls.h
+++ b/lib/pls/include/pls/pls.h
@@ -13,10 +13,10 @@ namespace pls {
 // 'basic' for-join APIs
 using internal::scheduling::scheduler;
 template<typename Function>
-void spawn(Function &&function) {
+static void spawn(Function &&function) {
   scheduler::spawn(std::forward<Function>(function));
 }
-void sync() {
+static void sync() {
   scheduler::sync();
 }
 
diff --git a/test/patterns_test.cpp b/test/patterns_test.cpp
index 3726626..0fddc82 100644
--- a/test/patterns_test.cpp
+++ b/test/patterns_test.cpp
@@ -7,6 +7,29 @@
 constexpr int MAX_NUM_TASKS = 32;
 constexpr int MAX_STACK_SIZE = 1024 * 8;
 
+TEST_CASE("spawn/sync invoke calls correctly", "[algorithms/invoke.h]") {
+  pls::scheduler scheduler{3, MAX_NUM_TASKS, MAX_STACK_SIZE};
+
+  std::atomic<int> num_run{0};
+  scheduler.perform_work([&] {
+    pls::spawn([&] {
+      num_run++;
+      while (num_run < 3);
+    });
+    pls::spawn([&] {
+      while (num_run < 1);
+      num_run++;
+      while (num_run < 3);
+    });
+    pls::spawn([&] {
+      while (num_run < 2);
+      num_run++;
+    });
+    pls::sync();
+    REQUIRE(num_run == 3);
+  });
+}
+
 TEST_CASE("parallel invoke calls correctly", "[algorithms/invoke.h]") {
   pls::scheduler scheduler{3, MAX_NUM_TASKS, MAX_STACK_SIZE};
 
diff --git a/test/scheduling_tests.cpp b/test/scheduling_tests.cpp
index 442fa17..826bdf5 100644
--- a/test/scheduling_tests.cpp
+++ b/test/scheduling_tests.cpp
@@ -1,12 +1,10 @@
 #include <catch.hpp>
 
-#include <vector>
 #include <atomic>
 
 #include "pls/internal/scheduling/traded_cas_field.h"
-#include "pls/internal/scheduling/task.h"
 #include "pls/internal/scheduling/external_trading_deque.h"
-#include "pls/internal/scheduling/scheduler.h"
+#include "pls/pls.h"
 
 using namespace pls::internal::scheduling;