diff --git a/tests/test_fake_data_creator.py b/tests/test_fake_data_creator.py
index b6fa188a1..3428c1a5a 100644
--- a/tests/test_fake_data_creator.py
+++ b/tests/test_fake_data_creator.py
@@ -1,3 +1,4 @@
+import numpy as np
 import os
 import tempfile
 import unittest
@@ -23,6 +24,19 @@ def test_create_fake_times(self):
         for i in range(7):
             self.assertAlmostEqual(times2[i], expected[i])
 
+    def test_add_fake_object(self):
+        img = RawImage(20, 10, 0.0, 1.0)  # All zero image.
+        p = PSF(np.full((3, 3), 1.0 / 9.0))  # Equal PSF.
+        add_fake_object(img, 5.5, 3.5, 100.0, p)
+
+        for r in range(10):
+            for c in range(20):
+                pix_val = img.get_pixel(r, c)
+                if abs(c - 5) <= 1 and abs(r - 3) <= 1:
+                    self.assertAlmostEqual(pix_val, 100.0 / 9.0, delta=0.001)
+                else:
+                    self.assertEqual(pix_val, 0.0)
+
     def test_create(self):
         times = create_fake_times(10)
         ds = FakeDataSet(256, 128, times)
diff --git a/tests/test_raw_image.py b/tests/test_raw_image.py
index 89cac4a2f..c98ef1794 100644
--- a/tests/test_raw_image.py
+++ b/tests/test_raw_image.py
@@ -124,11 +124,33 @@ def test_interpolated_add(self):
         # Get the original value using (r, c) lookup.
         org_val17 = img.get_pixel(1, 7)
 
+        # Get the sum of this pixel and its immediate neighbors.
+        org_sum = np.sum(img.image[0:3, 6:9])
+
         # Interpolated add uses the cartesian coordinates (x, y)
         img.interpolated_add(7, 1, 10.0)
         self.assertLess(img.get_pixel(1, 7), org_val17 + 10.0)
         self.assertGreater(img.get_pixel(1, 7), org_val17 + 2.0)
 
+        # Test we have added a total of 10.0 to the pixel and its neighbors.
+        new_sum = np.sum(img.image[0:3, 6:9])
+        self.assertAlmostEqual(new_sum - org_sum, 10.0)
+
+        # Add values right near the edge of the pixel.
+        org_val21 = img.get_pixel(2, 1)
+        org_val31 = img.get_pixel(3, 1)
+        org_val32 = img.get_pixel(3, 2)
+        org_val41 = img.get_pixel(4, 1)
+        img.interpolated_add(1.9, 3.5, 10.0)
+
+        # All the value should go to (3, 1) and (3, 2) with more going to (3, 1)
+        diff31 = img.get_pixel(3, 1) - org_val31
+        diff32 = img.get_pixel(3, 2) - org_val32
+        self.assertAlmostEqual(diff31 + diff32, 10.0)
+        self.assertGreater(diff31, diff32)
+        self.assertAlmostEqual(org_val21, img.get_pixel(2, 1))
+        self.assertAlmostEqual(org_val41, img.get_pixel(4, 1))
+
     def test_approx_equal(self):
         """Test RawImage pixel value setters."""
         img = RawImage(img=self.array, obs_time=10.0)
@@ -440,10 +462,10 @@ def test_convolve_psf_orientation_gpu(self):
         """Test convolution on GPU with a non-symmetric PSF"""
         self.convolve_psf_orientation_cpu("GPU")
 
-    # Stamp as is tested here and as it's used in StackSearch are heaven and earth
-    # TODO: Add proper tests
+    # Tests the basic cutout of a stamp from an image.  More advanced stamp
+    # construction is done in stamp_creator.cpp and tested in test_search.py.
     def test_make_stamp(self):
-        """Test stamp creation."""
+        """Tests the basic stamp creation."""
         img = RawImage(self.array)
         stamp = img.create_stamp(2.5, 2.5, 2, False)
         self.assertEqual(stamp.image.shape, (5, 5))