diff --git a/Tests/LibGfx/TestImageDecoder.cpp b/Tests/LibGfx/TestImageDecoder.cpp
index 069daa4d27..0afa5f2878 100644
--- a/Tests/LibGfx/TestImageDecoder.cpp
+++ b/Tests/LibGfx/TestImageDecoder.cpp
@@ -676,6 +676,18 @@ TEST_CASE(test_tiff_palette_alpha)
     EXPECT_EQ(frame.image->get_pixel(60, 75), Gfx::Color::NamedColor::Red);
 }
 
+TEST_CASE(test_tiff_alpha_predictor)
+{
+    auto file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("tiff/alpha_predictor.tiff"sv)));
+    EXPECT(Gfx::TIFFImageDecoderPlugin::sniff(file->bytes()));
+    auto plugin_decoder = TRY_OR_FAIL(Gfx::TIFFImageDecoderPlugin::create(file->bytes()));
+
+    auto frame = TRY_OR_FAIL(expect_single_frame_of_size(*plugin_decoder, { 400, 300 }));
+
+    EXPECT_EQ(frame.image->get_pixel(0, 0).alpha(), 255);
+    EXPECT_EQ(frame.image->get_pixel(60, 75), Gfx::Color::NamedColor::Red);
+}
+
 TEST_CASE(test_tiff_16_bits)
 {
     auto file = TRY_OR_FAIL(Core::MappedFile::map(TEST_INPUT("tiff/16_bits.tiff"sv)));
diff --git a/Tests/LibGfx/test-inputs/tiff/alpha_predictor.tiff b/Tests/LibGfx/test-inputs/tiff/alpha_predictor.tiff
new file mode 100644
index 0000000000..b727ba2c30
Binary files /dev/null and b/Tests/LibGfx/test-inputs/tiff/alpha_predictor.tiff differ
diff --git a/Userland/Libraries/LibGfx/ImageFormats/TIFFLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/TIFFLoader.cpp
index ff5bedee69..d8389986b1 100644
--- a/Userland/Libraries/LibGfx/ImageFormats/TIFFLoader.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/TIFFLoader.cpp
@@ -267,6 +267,8 @@ private:
                         color.set_red(last_color->red() + color.red());
                         color.set_green(last_color->green() + color.green());
                         color.set_blue(last_color->blue() + color.blue());
+                        if (alpha_channel_index().has_value())
+                            color.set_alpha(last_color->alpha() + color.alpha());
                     }
 
                     last_color = color;