diff --git a/Tests/test_file_gd.py b/Tests/test_file_gd.py
index d512df284e1..806532c17ec 100644
--- a/Tests/test_file_gd.py
+++ b/Tests/test_file_gd.py
@@ -4,6 +4,8 @@
 
 from PIL import GdImageFile, UnidentifiedImageError
 
+from .helper import assert_image_similar_tofile
+
 TEST_GD_FILE = "Tests/images/hopper.gd"
 
 
@@ -11,6 +13,7 @@ def test_sanity() -> None:
     with GdImageFile.open(TEST_GD_FILE) as im:
         assert im.size == (128, 128)
         assert im.format == "GD"
+        assert_image_similar_tofile(im.convert("RGB"), "Tests/images/hopper.jpg", 14)
 
 
 def test_bad_mode() -> None:
diff --git a/src/PIL/GdImageFile.py b/src/PIL/GdImageFile.py
index fc4801e9d1c..891225ce2fd 100644
--- a/src/PIL/GdImageFile.py
+++ b/src/PIL/GdImageFile.py
@@ -56,7 +56,7 @@ def _open(self) -> None:
             msg = "Not a valid GD 2.x .gd file"
             raise SyntaxError(msg)
 
-        self._mode = "L"  # FIXME: "P"
+        self._mode = "P"
         self._size = i16(s, 2), i16(s, 4)
 
         true_color = s[6]
@@ -68,14 +68,14 @@ def _open(self) -> None:
             self.info["transparency"] = tindex
 
         self.palette = ImagePalette.raw(
-            "XBGR", s[7 + true_color_offset + 4 : 7 + true_color_offset + 4 + 256 * 4]
+            "RGBX", s[7 + true_color_offset + 6 : 7 + true_color_offset + 6 + 256 * 4]
         )
 
         self.tile = [
             ImageFile._Tile(
                 "raw",
                 (0, 0) + self.size,
-                7 + true_color_offset + 4 + 256 * 4,
+                7 + true_color_offset + 6 + 256 * 4,
                 "L",
             )
         ]