diff --git a/Tests/test_color_lut.py b/Tests/test_color_lut.py
index 30b8de279..3bfb05f02 100644
--- a/Tests/test_color_lut.py
+++ b/Tests/test_color_lut.py
@@ -198,7 +198,24 @@ class TestColorLut3DCoreAPI(PillowTestCase):
                     -1, -1,  2,   2, -1,  2,
                     -1,  2,  2,   2,  2,  2,
                 ])).load()
+        self.assertEqual(transformed[0, 0], (0, 0, 255))
+        self.assertEqual(transformed[50, 50], (0, 0, 255))
+        self.assertEqual(transformed[255, 0], (0, 255, 255))
+        self.assertEqual(transformed[205, 50], (0, 255, 255))
+        self.assertEqual(transformed[0, 255], (255, 0, 0))
+        self.assertEqual(transformed[50, 205], (255, 0, 0))
+        self.assertEqual(transformed[255, 255], (255, 255, 0))
+        self.assertEqual(transformed[205, 205], (255, 255, 0))
 
+        transformed = im._new(im.im.color_lut_3d('RGB', Image.LINEAR,
+                3, 2, 2, 2,
+                [
+                    -3, -3, -3,   5, -3, -3,
+                    -3,  5, -3,   5,  5, -3,
+
+                    -3, -3,  5,   5, -3,  5,
+                    -3,  5,  5,   5,  5,  5,
+                ])).load()
         self.assertEqual(transformed[0, 0], (0, 0, 255))
         self.assertEqual(transformed[50, 50], (0, 0, 255))
         self.assertEqual(transformed[255, 0], (0, 255, 255))
@@ -257,6 +274,11 @@ class TestColorLut3DFilter(PillowTestCase):
             0.0, 0.0, 0.0,  0.25, 0.0, 0.0,  0.5, 0.0, 0.0,  0.75, 0.0, 0.0,
             1.0, 0.0, 0.0,  0.0, 0.25, 0.0,  0.25, 0.25, 0.0,  0.5, 0.25, 0.0])
 
+        g = Image.linear_gradient('L')
+        im = Image.merge('RGB', [g, g.transpose(Image.ROTATE_90),
+                                 g.transpose(Image.ROTATE_180)])
+        self.assertEqual(im, im.filter(flt))
+
         flt = ImageFilter.Color3DLUT.generate(5, channels=4,
             callback=lambda r, g, b: (b, r, g, (r+g+b) / 2))
         self.assertEqual(tuple(flt.size), (5, 5, 5))
diff --git a/src/libImaging/Resample.c b/src/libImaging/Resample.c
index 29a6cce1d..6fae2081d 100644
--- a/src/libImaging/Resample.c
+++ b/src/libImaging/Resample.c
@@ -83,7 +83,16 @@ static struct filter LANCZOS = { lanczos_filter, 3.0 };
 #define PRECISION_BITS (32 - 8 - 2)
 
 
-UINT8 _clip8_lookups[1024] = {
+/* Handles values form -640 to 639. */
+UINT8 _clip8_lookups[1280] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -147,10 +156,18 @@ UINT8 _clip8_lookups[1024] = {
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
     255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
-    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
 };
 
-UINT8 *clip8_lookups = &_clip8_lookups[512];
+UINT8 *clip8_lookups = &_clip8_lookups[640];
 
 static inline UINT8 clip8(int in)
 {