diff --git a/romancal/outlier_detection/tests/test_outlier_detection.py b/romancal/outlier_detection/tests/test_outlier_detection.py
index be7901187..75127f000 100644
--- a/romancal/outlier_detection/tests/test_outlier_detection.py
+++ b/romancal/outlier_detection/tests/test_outlier_detection.py
@@ -1,3 +1,4 @@
+import gc
 import os
 
 import astropy.units as u
@@ -80,6 +81,7 @@ def test_outlier_valid_input_asn(tmp_path, base_image, create_mock_asn_file):
             res.shelve(m, i, modify=False)
             del m
     del res
+    gc.collect(2)
 
 
 def test_outlier_valid_input_modelcontainer(tmp_path, base_image):
diff --git a/romancal/tweakreg/tests/test_tweakreg.py b/romancal/tweakreg/tests/test_tweakreg.py
index 9929e3393..565d961ee 100644
--- a/romancal/tweakreg/tests/test_tweakreg.py
+++ b/romancal/tweakreg/tests/test_tweakreg.py
@@ -557,6 +557,8 @@ def test_tweakreg_returns_modellibrary_on_association_file_as_input(
         for i, model in enumerate(res):
             assert model.meta.cal_step.tweakreg == "COMPLETE"
             res.shelve(model, i, modify=False)
+        del model
+    del res
 
 
 def test_tweakreg_returns_modellibrary_on_list_of_asdf_file_as_input(
@@ -755,6 +757,8 @@ def test_tweakreg_combine_custom_catalogs_and_asn_file(tmp_path, base_image):
             assert (model.data == target.data).all()
 
             res.shelve(model, i, modify=False)
+        del model
+    del res
 
 
 @pytest.mark.parametrize(
@@ -879,6 +883,8 @@ def test_tweakreg_parses_asn_correctly(tmp_path, base_image):
         assert (models[1].data == img_2.data).all()
 
         [res.shelve(m, i, modify=False) for i, m in enumerate(models)]
+        del models
+    del res
 
 
 def test_fit_results_in_meta(tmp_path, base_image):