diff --git a/cpp/pmtiles.hpp b/cpp/pmtiles.hpp
index f1685e1..0b6bd91 100644
--- a/cpp/pmtiles.hpp
+++ b/cpp/pmtiles.hpp
@@ -16,6 +16,7 @@ const uint8_t TILETYPE_MVT = 0x1;
 const uint8_t TILETYPE_PNG = 0x2;
 const uint8_t TILETYPE_JPEG = 0x3;
 const uint8_t TILETYPE_WEBP = 0x4;
+const uint8_t TILETYPE_AVIF = 0x5;
 
 const uint8_t COMPRESSION_UNKNOWN = 0x0;
 const uint8_t COMPRESSION_NONE = 0x1;
diff --git a/python/pmtiles/convert.py b/python/pmtiles/convert.py
index bc7c82a..08b0827 100644
--- a/python/pmtiles/convert.py
+++ b/python/pmtiles/convert.py
@@ -35,6 +35,8 @@ def mbtiles_to_header_json(mbtiles_metadata):
         header["tile_type"] = TileType.JPEG
     elif tile_format == "webp":
         header["tile_type"] = TileType.WEBP
+    elif tile_format == "avif":
+        header["tile_type"] = TileType.AVIF
     else:
         header["tile_type"] = TileType.UNKNOWN
 
diff --git a/python/pmtiles/tile.py b/python/pmtiles/tile.py
index b50729a..980f041 100644
--- a/python/pmtiles/tile.py
+++ b/python/pmtiles/tile.py
@@ -142,6 +142,7 @@ class TileType(Enum):
     PNG = 2
     JPEG = 3
     WEBP = 4
+    AVIF = 5
 
 
 def deserialize_directory(buf):