diff --git a/Tests/test_file_avif.py b/Tests/test_file_avif.py
index 1b3eb7d8b0b..191591bac5a 100644
--- a/Tests/test_file_avif.py
+++ b/Tests/test_file_avif.py
@@ -25,6 +25,7 @@
     assert_image,
     assert_image_similar,
     assert_image_similar_tofile,
+    has_feature_version,
     hopper,
     skip_if_tsan,
     skip_unless_feature,
@@ -133,13 +134,14 @@ def test_read(self) -> None:
                 image, "Tests/images/avif/hopper_avif_write.png", 11.5
             )
 
-    @skip_unless_feature_version("avif", "1.3.0")
-    def test_write_l(self) -> None:
-        im = hopper("L")
-        reloaded = roundtrip(im)
+    @pytest.mark.parametrize("mode", ["1", "L", "I", "I;16", "F"])
+    def test_write_grayscale(self, mode: str) -> None:
+        im = hopper(mode)
+        reloaded: Image.Image = roundtrip(im)
 
-        assert reloaded.mode == "L"
-        assert_image_similar(reloaded, im, 1.69)
+        if not has_feature_version("avif", "1.3.0"):
+            reloaded = reloaded.convert("L")
+        assert_image_similar(reloaded, im.convert("L"), 1.69)
 
     def test_write_rgb(self, tmp_path: Path) -> None:
         """
@@ -193,6 +195,8 @@ def test_encoder_finish_none_error(
         """Save should raise an OSError if AvifEncoder.finish returns None"""
 
         class _mock_avif:
+            libavif_version = "1.3.0"
+
             class AvifEncoder:
                 def __init__(self, *args: Any) -> None:
                     pass
diff --git a/src/PIL/AvifImagePlugin.py b/src/PIL/AvifImagePlugin.py
index dd87a508313..4222ac6add2 100644
--- a/src/PIL/AvifImagePlugin.py
+++ b/src/PIL/AvifImagePlugin.py
@@ -239,6 +239,11 @@ def _save(
         advanced,
     )
 
+    supported_modes = {"RGB", "RGBA"}
+    if tuple(int(v) for v in _avif.libavif_version.split(".")) >= (1, 3):
+        # AVIF_RGB_FORMAT_GRAY was only added in libavif 1.3.0
+        supported_modes.add("L")
+
     # Add each frame
     frame_idx = 0
     frame_duration = 0
@@ -249,10 +254,10 @@ def _save(
             for frame in ImageSequence.Iterator(ims):
                 # Make sure image mode is supported
                 rawmode = frame.mode
-                if ims.mode not in {"L", "RGB", "RGBA"}:
+                if ims.mode not in supported_modes:
                     if ims.has_transparency_data:
                         rawmode = "RGBA"
-                    elif ims.mode in grayscale_modes:
+                    elif ims.mode in grayscale_modes and "L" in supported_modes:
                         rawmode = "L"
                     else:
                         rawmode = "RGB"