diff --git a/Tests/test_file_libtiff.py b/Tests/test_file_libtiff.py
index d83c584b5da..a43548ae0f3 100644
--- a/Tests/test_file_libtiff.py
+++ b/Tests/test_file_libtiff.py
@@ -497,8 +497,8 @@ def test_cmyk_save(self, tmp_path):
         im.save(out, compression="tiff_adobe_deflate")
         assert_image_equal_tofile(im, out)
 
-    def test_palette_save(self, tmp_path):
-        im = hopper("P")
+    @pytest.mark.parametrize("im", (hopper("P"), Image.new("P", (1, 1), "#000")))
+    def test_palette_save(self, im, tmp_path):
         out = str(tmp_path / "temp.tif")
 
         TiffImagePlugin.WRITE_LIBTIFF = True
diff --git a/src/PIL/TiffImagePlugin.py b/src/PIL/TiffImagePlugin.py
index 000429991d6..6966467d66e 100644
--- a/src/PIL/TiffImagePlugin.py
+++ b/src/PIL/TiffImagePlugin.py
@@ -1676,7 +1676,12 @@ def _save(im, fp, filename):
 
     if im.mode in ["P", "PA"]:
         lut = im.im.getpalette("RGB", "RGB;L")
-        ifd[COLORMAP] = tuple(v * 256 for v in lut)
+        colormap = []
+        colors = len(lut) // 3
+        for i in range(3):
+            colormap += [v * 256 for v in lut[colors * i : colors * (i + 1)]]
+            colormap += [0] * (256 - colors)
+        ifd[COLORMAP] = colormap
     # data orientation
     stride = len(bits) * ((im.size[0] * bits[0] + 7) // 8)
     # aim for given strip size (64 KB by default) when using libtiff writer