diff --git a/Tests/test_image_getpixel.py b/Tests/test_image_getpixel.py
index ffa6a9c52..67f5904a2 100644
--- a/Tests/test_image_getpixel.py
+++ b/Tests/test_image_getpixel.py
@@ -11,49 +11,39 @@ def color(mode):
     else:
         return tuple(range(1, bands+1))
 
-def test_pixel():
 
-    def pixel(mode):
+
+def check(mode, c=None):
+    if not c:
         c = color(mode)
-        im = Image.new(mode, (1, 1), None)
-        im.putpixel((0, 0), c)
-        return im.getpixel((0, 0))
+        
+    #check putpixel
+    im = Image.new(mode, (1, 1), None)
+    im.putpixel((0, 0), c)
+    assert_equal(im.getpixel((0, 0)), c,
+                 "put/getpixel roundtrip failed for mode %s, color %s" %
+                 (mode, c))
+    
+    # check inital color
+    im = Image.new(mode, (1, 1), c)
+    assert_equal(im.getpixel((0, 0)), c,
+                 "initial color failed for mode %s, color %s " %
+                 (mode, color))
 
-    assert_equal(pixel("1"), 1)
-    assert_equal(pixel("L"), 1)
-    assert_equal(pixel("LA"), (1, 2))
-    assert_equal(pixel("I"), 1)
-    assert_equal(pixel("I;16"), 1)
-    assert_equal(pixel("I;16B"), 1)
-    assert_equal(pixel("F"), 1.0)
-    assert_equal(pixel("P"), 1)
-    assert_equal(pixel("PA"), (1, 2))
-    assert_equal(pixel("RGB"), (1, 2, 3))
-    assert_equal(pixel("RGBA"), (1, 2, 3, 4))
-    assert_equal(pixel("RGBX"), (1, 2, 3, 4))
-    assert_equal(pixel("CMYK"), (1, 2, 3, 4))
-    assert_equal(pixel("YCbCr"), (1, 2, 3))
+def test_basic():    
+    for mode in ("1", "L", "LA", "I", "I;16", "I;16B", "F",
+                 "P", "PA", "RGB", "RGBA", "RGBX", "CMYK","YCbCr"):
+        check(mode)
 
-def test_image():
-
-    def pixel(mode):
-        im = Image.new(mode, (1, 1), color(mode))
-        return im.getpixel((0, 0))
-
-    assert_equal(pixel("1"), 1)
-    assert_equal(pixel("L"), 1)
-    assert_equal(pixel("LA"), (1, 2))
-    assert_equal(pixel("I"), 1)
-    assert_equal(pixel("I;16"), 1)
-    assert_equal(pixel("I;16B"), 1)
-    assert_equal(pixel("F"), 1.0)
-    assert_equal(pixel("P"), 1)
-    assert_equal(pixel("PA"), (1, 2))
-    assert_equal(pixel("RGB"), (1, 2, 3))
-    assert_equal(pixel("RGBA"), (1, 2, 3, 4))
-    assert_equal(pixel("RGBX"), (1, 2, 3, 4))
-    assert_equal(pixel("CMYK"), (1, 2, 3, 4))
-    assert_equal(pixel("YCbCr"), (1, 2, 3))
+def test_signedness():
+    # see https://github.com/python-imaging/Pillow/issues/452
+    # pixelaccess is using signed int* instead of uint*
+    for mode in ("I;16", "I;16B"):
+        check(mode, 2**15-1)
+        check(mode, 2**15)
+        check(mode, 2**15+1)
+        check(mode, 2**16-1)
 
+                
 
 
diff --git a/_imaging.c b/_imaging.c
index 13466f00a..078961da4 100644
--- a/_imaging.c
+++ b/_imaging.c
@@ -463,7 +463,7 @@ getpixel(Imaging im, ImagingAccess access, int x, int y)
 {
     union {
       UINT8 b[4];
-      INT16 h;
+      UINT16 h;
       INT32 i;
       FLOAT32 f;
     } pixel;
diff --git a/libImaging/Access.c b/libImaging/Access.c
index 70eb1af4c..62c97f3a3 100644
--- a/libImaging/Access.c
+++ b/libImaging/Access.c
@@ -94,11 +94,11 @@ static void
 get_pixel_16L(Imaging im, int x, int y, void* color)
 {
     UINT8* in = (UINT8*) &im->image[y][x+x];
-    INT16* out = color;
+    UINT16* out = color;
 #ifdef WORDS_BIGENDIAN
     out[0] = in[0] + (in[1]<<8);
 #else
-    out[0] = *(INT16*) in;
+    out[0] = *(UINT16*) in;
 #endif
 }
 
@@ -106,9 +106,9 @@ static void
 get_pixel_16B(Imaging im, int x, int y, void* color)
 {
     UINT8* in = (UINT8*) &im->image[y][x+x];
-    INT16* out = color;
+    UINT16* out = color;
 #ifdef WORDS_BIGENDIAN
-    out[0] = *(INT16*) in;
+    out[0] = *(UINT16*) in;
 #else
     out[0] = in[1] + (in[0]<<8);
 #endif