diff --git a/test/data_structures_test.cpp b/test/data_structures_test.cpp
index 0b27ee0..dda7b26 100644
--- a/test/data_structures_test.cpp
+++ b/test/data_structures_test.cpp
@@ -23,9 +23,9 @@ TEST_CASE("aligned stack stores objects correctly", "[internal/data_structures/a
     std::array<char, 64> small_data_two{};
     std::array<char, 1> small_data_three{'A'};
 
-    auto pointer_one = stack.push(small_data_one);
-    auto pointer_two = stack.push(small_data_two);
-    auto pointer_three = stack.push(small_data_three);
+    auto pointer_one = stack.push<decltype(small_data_one)>(small_data_one);
+    auto pointer_two = stack.push<decltype(small_data_two)>(small_data_two);
+    auto pointer_three = stack.push<decltype(small_data_three)>(small_data_three);
 
     REQUIRE(reinterpret_cast<std::uintptr_t>(pointer_one) % system_details::CACHE_LINE_SIZE == 0);
     REQUIRE(reinterpret_cast<std::uintptr_t>(pointer_two) % system_details::CACHE_LINE_SIZE == 0);
@@ -36,8 +36,8 @@ TEST_CASE("aligned stack stores objects correctly", "[internal/data_structures/a
     std::array<char, 5> small_data_one{'a', 'b', 'c', 'd', 'e'};
     std::array<char, system_details::CACHE_LINE_SIZE + 10> big_data_one{};
 
-    auto big_pointer_one = stack.push(big_data_one);
-    auto small_pointer_one = stack.push(small_data_one);
+    auto big_pointer_one = stack.push<decltype(big_data_one)>(big_data_one);
+    auto small_pointer_one = stack.push<decltype(small_data_one)>(small_data_one);
 
     REQUIRE(reinterpret_cast<std::uintptr_t>(big_pointer_one) % system_details::CACHE_LINE_SIZE == 0);
     REQUIRE(reinterpret_cast<std::uintptr_t>(small_pointer_one) % system_details::CACHE_LINE_SIZE == 0);
@@ -46,7 +46,7 @@ TEST_CASE("aligned stack stores objects correctly", "[internal/data_structures/a
   SECTION("stack correctly stores and retrieves objects") {
     std::array<char, 5> data_one{'a', 'b', 'c', 'd', 'e'};
 
-    stack.push(data_one);
+    stack.push<decltype(data_one)>(data_one);
     auto retrieved_data = stack.pop<std::array<char, 5>>();
 
     REQUIRE(retrieved_data == std::array<char, 5>{'a', 'b', 'c', 'd', 'e'});
@@ -57,13 +57,13 @@ TEST_CASE("aligned stack stores objects correctly", "[internal/data_structures/a
     std::array<char, 64> small_data_two{};
     std::array<char, 1> small_data_three{'A'};
 
-    auto pointer_one = stack.push(small_data_one);
-    auto pointer_two = stack.push(small_data_two);
-    auto pointer_three = stack.push(small_data_three);
-    stack.pop<typeof(small_data_three)>();
-    stack.pop<typeof(small_data_two)>();
-    auto pointer_four = stack.push(small_data_two);
-    auto pointer_five = stack.push(small_data_three);
+    auto pointer_one = stack.push<decltype(small_data_one)>(small_data_one);
+    auto pointer_two = stack.push<decltype(small_data_two)>(small_data_two);
+    auto pointer_three = stack.push<decltype(small_data_three)>(small_data_three);
+    stack.pop<decltype(small_data_three)>();
+    stack.pop<decltype(small_data_two)>();
+    auto pointer_four = stack.push<decltype(small_data_two)>(small_data_two);
+    auto pointer_five = stack.push<decltype(small_data_three)>(small_data_three);
 
     REQUIRE(reinterpret_cast<std::uintptr_t>(pointer_one) % system_details::CACHE_LINE_SIZE == 0);
     REQUIRE(reinterpret_cast<std::uintptr_t>(pointer_two) % system_details::CACHE_LINE_SIZE == 0);
@@ -143,11 +143,12 @@ TEST_CASE("work stealing deque stores objects correctly", "[internal/data_struct
   work_stealing_deque<int> deque{&stack};
 
   int one = 1, two = 2, three = 3, four = 4;
+  auto no_op = [](int *) {}; // Empty-Callback
 
   SECTION("add and remove items form the tail") {
-    deque.push_tail(one);
-    deque.push_tail(two);
-    deque.push_tail(three);
+    deque.push_tail<int>(no_op, one);
+    deque.push_tail<int>(no_op, two);
+    deque.push_tail<int>(no_op, three);
 
     REQUIRE(*deque.pop_tail() == three);
     REQUIRE(*deque.pop_tail() == two);
@@ -155,17 +156,17 @@ TEST_CASE("work stealing deque stores objects correctly", "[internal/data_struct
   }
 
   SECTION("handles getting empty by popping the tail correctly") {
-    deque.push_tail(one);
+    deque.push_tail<int>(no_op, one);
     REQUIRE(*deque.pop_tail() == one);
 
-    deque.push_tail(two);
+    deque.push_tail<int>(no_op, two);
     REQUIRE(*deque.pop_tail() == two);
   }
 
   SECTION("remove items form the head") {
-    deque.push_tail(one);
-    deque.push_tail(two);
-    deque.push_tail(three);
+    deque.push_tail<int>(no_op, one);
+    deque.push_tail<int>(no_op, two);
+    deque.push_tail<int>(no_op, three);
 
     REQUIRE(*deque.pop_head() == one);
     REQUIRE(*deque.pop_head() == two);
@@ -173,52 +174,48 @@ TEST_CASE("work stealing deque stores objects correctly", "[internal/data_struct
   }
 
   SECTION("handles getting empty by popping the head correctly") {
-    deque.push_tail(one);
+    deque.push_tail<int>(no_op, one);
     REQUIRE(*deque.pop_head() == one);
 
-    deque.push_tail(two);
+    deque.push_tail<int>(no_op, two);
     REQUIRE(*deque.pop_head() == two);
   }
 
   SECTION("handles getting empty by popping the head and tail correctly") {
-    deque.push_tail(one);
+    deque.push_tail<int>(no_op, one);
     REQUIRE(*deque.pop_tail() == one);
 
-    deque.push_tail(two);
+    deque.push_tail<int>(no_op, two);
     REQUIRE(*deque.pop_head() == two);
 
-    deque.push_tail(three);
+    deque.push_tail<int>(no_op, three);
     REQUIRE(*deque.pop_tail() == three);
   }
 
   SECTION("handles jumps bigger 1 correctly") {
-    deque.push_tail(one);
-    deque.push_tail(two);
+    deque.push_tail<int>(no_op, one);
+    deque.push_tail<int>(no_op, two);
     REQUIRE(*deque.pop_tail() == two);
 
-    deque.push_tail(three);
-    deque.push_tail(four);
+    deque.push_tail<int>(no_op, three);
+    deque.push_tail<int>(no_op, four);
     REQUIRE(*deque.pop_head() == one);
     REQUIRE(*deque.pop_head() == three);
     REQUIRE(*deque.pop_head() == four);
   }
 
   SECTION("handles stack reset 1 correctly when emptied by tail") {
-    deque.push_tail(one);
+    deque.push_tail<int>(no_op, one);
     auto state = deque.save_state();
-    deque.push_tail(two);
+    deque.push_tail<int>(no_op, two);
     REQUIRE(*deque.pop_tail() == two);
 
     deque.release_memory_until(state);
     REQUIRE(*deque.pop_tail() == one);
 
-    deque.push_tail(three);
-    deque.push_tail(four);
+    deque.push_tail<int>(no_op, three);
+    deque.push_tail<int>(no_op, four);
     REQUIRE(*deque.pop_head() == three);
     REQUIRE(*deque.pop_tail() == four);
   }
-
-  SECTION("synces correctly") {
-
-  }
 }
diff --git a/test/scheduling_tests.cpp b/test/scheduling_tests.cpp
index 710fc80..481a75e 100644
--- a/test/scheduling_tests.cpp
+++ b/test/scheduling_tests.cpp
@@ -12,7 +12,7 @@ class once_sub_task : public task {
   void execute_internal() override {
     (*counter_)++;
     for (int i = 0; i < children_; i++) {
-      spawn_child(once_sub_task(counter_, children_ - 1));
+      spawn_child<once_sub_task>(counter_, children_ - 1);
     }
   }
 
@@ -32,7 +32,7 @@ class force_steal_sub_task : public task {
     (*overall_counter_)--;
     if (overall_counter_->load() > 0) {
       std::atomic<int> counter{1};
-      spawn_child(force_steal_sub_task(&counter, overall_counter_));
+      spawn_child<force_steal_sub_task>(&counter, overall_counter_);
       while (counter.load() > 0); // Spin...
     }
 
@@ -56,8 +56,7 @@ TEST_CASE("tbb task are scheduled correctly", "[internal/scheduling/fork_join_ta
     std::atomic<int> counter{0};
 
     my_scheduler.perform_work([&]() {
-      once_sub_task sub_task{&counter, start_counter};
-      scheduler::spawn_child(sub_task);
+      scheduler::spawn_child<once_sub_task>(&counter, start_counter);
     });
 
     REQUIRE(counter.load() == total_tasks);
@@ -68,8 +67,7 @@ TEST_CASE("tbb task are scheduled correctly", "[internal/scheduling/fork_join_ta
     scheduler my_scheduler{&my_scheduler_memory, 8};
     my_scheduler.perform_work([&]() {
       std::atomic<int> dummy_parent{1}, overall_counter{8};
-      force_steal_sub_task sub_task{&dummy_parent, &overall_counter};
-      scheduler::spawn_child(sub_task);
+      scheduler::spawn_child<force_steal_sub_task>(&dummy_parent, &overall_counter);
 
       // Required, as child operates on our stack's memory!!!
       scheduler::wait_for_all();