diff --git a/eessi/testsuite/hooks.py b/eessi/testsuite/hooks.py
index 751b3ffb..65c51c87 100644
--- a/eessi/testsuite/hooks.py
+++ b/eessi/testsuite/hooks.py
@@ -105,6 +105,12 @@ def _assign_num_tasks_per_node(test: rfm.RegressionTest, num_per: int = 1):
     - num_tasks_per_node = num_per
     - num_cpus_per_task = test.default_num_cpus_per_node / num_tasks_per_node
     """
+
+    # OSU test inherits a default num_tasks_per_node = 1 from hpctestlib.
+    # There has to be a condition where a non-default value of num_per replaces the original num_tasks_per_node.
+    if test.num_tasks_per_node and num_per != 1:
+        if test.num_tasks_per_node != num_per:
+            test.num_tasks_per_node = num_per
     # neither num_tasks_per_node nor num_cpus_per_task are set
     if not test.num_tasks_per_node and not test.num_cpus_per_task:
         test.num_tasks_per_node = num_per
diff --git a/eessi/testsuite/tests/apps/osu.py b/eessi/testsuite/tests/apps/osu.py
index 42451700..28e6b2f8 100644
--- a/eessi/testsuite/tests/apps/osu.py
+++ b/eessi/testsuite/tests/apps/osu.py
@@ -103,22 +103,18 @@ def set_num_tasks(self):
         """ Setting scales as tags. """
         hooks.set_tag_scale(self)
 
-    @run_after('init')
+    @run_after('setup')
     def set_num_tasks_per_node(self):
+        """ Setting number of tasks per node and cpus per task in this function.
+        This function sets num_cpus_per_task for 1 node and 2 node options where 
+        the request is for full nodes."""
         if(SCALES.get(self.scale).get('num_nodes') == 1):
-            self.num_tasks_per_node = 2
+            print("test: ", self.num_tasks_per_node)
+            hooks.assign_tasks_per_compute_unit(self,
+                                                   COMPUTE_UNIT.get(NODE,
+                                                                    'node'), 2)
         else:
-            self.num_tasks_per_node = 1
-
-    @run_after('setup')
-    def set_num_cpus_per_task(self):
-        """ Since num_tasks_per_node is already set. This function sets
-        num_cpus_per_task for 1 node and 2 node options where the request is
-        for full nodes."""
-        if(SCALES.get(self.scale).get('num_nodes') >= 1 and
-           SCALES.get(self.scale).get('node_part', 0) == 1):
-            hooks.assign_one_task_per_compute_unit(self,
-                                                   COMPUTE_UNIT.get(CPU, 'cpu'))
+            hooks.assign_tasks_per_compute_unit(self, COMPUTE_UNIT.get(NODE, 'node'))
 
     @run_after('setup')
     def set_num_gpus_per_node(self):