diff --git a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTiles.java b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTiles.java
index 53ac3db7c..0e83c018a 100644
--- a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTiles.java
+++ b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTiles.java
@@ -365,7 +365,7 @@ public static Directories buildRootLeaves(List<Entry> entries, int leafSize) thr
   public static Directories optimizeDirectories(List<Entry> entries, int targetRootLenght)
       throws IOException {
     if (entries.size() < 16384) {
-      byte[] rootBytes = null;
+      byte[] rootBytes;
       try (var rootOutput = new ByteArrayOutputStream();
           var rootDataOutput = new LittleEndianDataOutputStream(rootOutput)) {
         serializeEntries(rootDataOutput, entries);
@@ -376,9 +376,9 @@ public static Directories optimizeDirectories(List<Entry> entries, int targetRoo
       }
     }
 
-    double leafSize = (double) entries.size() / 3500d;
-    if (leafSize < 4096d) {
-      leafSize = 4096d;
+    double leafSize = (double) entries.size() / 3500;
+    if (leafSize < 4096) {
+      leafSize = 4096;
     }
     for (;;) {
       var directories = buildRootLeaves(entries, (int) leafSize);
@@ -387,6 +387,5 @@ public static Directories optimizeDirectories(List<Entry> entries, int targetRoo
       }
       leafSize = leafSize * 1.2;
     }
-
   }
 }
diff --git a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesStore.java b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesStore.java
index 272b4c95a..5c06d2197 100644
--- a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesStore.java
+++ b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesStore.java
@@ -20,6 +20,9 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import org.apache.baremaps.tilestore.TileCoord;
 import org.apache.baremaps.tilestore.TileStore;
 import org.apache.baremaps.tilestore.TileStoreException;
@@ -31,6 +34,21 @@ public class PMTilesStore implements TileStore {
   public PMTilesStore(Path path) {
     try {
       this.writer = new PMTilesWriter(path);
+
+      var metadata = new HashMap<String, Object>();
+      metadata.put("name", "baremaps");
+      metadata.put("type", "baselayer");
+      metadata.put("version", "0.0.1");
+      metadata.put("description", "PMTiles generated by Baremaps");
+      metadata.put("attribution", "OpenStreetMap contributors");
+      metadata.put("vector_layers", List.of(
+          "aerialway", "aeroway", "amenity", "attraction",
+          "barrier", "boundary", "building", "highway", "landuse",
+          "leisure", "man_made", "natural", "ocean", "point",
+          "power", "railway", "route", "waterway")
+          .stream().map(s -> Map.of("id", s)).toList());
+      this.writer.writeMetadata(metadata);
+
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
diff --git a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesWriter.java b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesWriter.java
index 66566dffa..eeb65c4e7 100644
--- a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesWriter.java
+++ b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/PMTilesWriter.java
@@ -30,6 +30,8 @@ public class PMTilesWriter {
 
   private final Path path;
 
+  private Map<String, Object> metadata = new HashMap<>();
+
   private final List<Entry> entries;
 
   private final Map<Long, Long> tileHashToOffset;
@@ -52,7 +54,11 @@ public PMTilesWriter(Path path, List<Entry> entries, Map<Long, Long> tileHashToO
     this.tilePath = Files.createTempFile(path.getParent(), "tiles", ".tmp");
   }
 
-  public synchronized void writeTile(int z, int x, int y, byte[] bytes) throws IOException {
+  public void writeMetadata(Map<String, Object> metadata) {
+    this.metadata = metadata;
+  }
+
+  public void writeTile(int z, int x, int y, byte[] bytes) throws IOException {
     // Write the tile
     var tileId = PMTiles.zxyToTileId(z, x, y);
     var tileLength = bytes.length;
@@ -93,20 +99,7 @@ public void finalize() throws IOException {
       entries.sort(Comparator.comparingLong(Entry::getTileId));
     }
 
-    var metadataMap = new HashMap<String, Object>();
-    metadataMap.put("name", "baremaps");
-    metadataMap.put("type", "baselayer");
-    metadataMap.put("version", "0.0.1");
-    metadataMap.put("description", "PMTiles generated by Baremaps");
-    metadataMap.put("attribution", "OpenStreetMap contributors");
-    metadataMap.put("vector_layers", List.of("aerialway", "aeroway", "amenity", "attraction",
-        "barrier", "boundary", "building", "highway", "landuse",
-        "leisure", "man_made", "natural", "ocean", "point",
-        "power", "railway", "route", "waterway")
-        .stream().map(s -> Map.of("id", s)).toList());
-
-
-    var metadataBytes = new ObjectMapper().writeValueAsBytes(metadataMap);
+    var metadataBytes = new ObjectMapper().writeValueAsBytes(metadata);
 
     var directories = PMTiles.optimizeDirectories(entries, 16247);
     var rootOffset = 127;
@@ -127,7 +120,7 @@ public void finalize() throws IOException {
 
     header.setInternalCompression(Compression.None);
     header.setTileCompression(Compression.Gzip);
-    header.setTileType(TileType.Mvt);
+    header.setTileType(TileType.mvt);
     header.setRootOffset(rootOffset);
     header.setRootLength(rootLength);
     header.setMetadataOffset(metadataOffset);
diff --git a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/TileType.java b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/TileType.java
index 2231fd67e..335bc4884 100644
--- a/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/TileType.java
+++ b/baremaps-core/src/main/java/org/apache/baremaps/tilestore/pmtiles/TileType.java
@@ -18,10 +18,10 @@
 package org.apache.baremaps.tilestore.pmtiles;
 
 enum TileType {
-  Unknown,
-  Mvt,
-  Png,
-  Jpeg,
-  Webp,
-  Avif,
+  unknown,
+  mvt,
+  png,
+  jpeg,
+  webp,
+  avif,
 }
diff --git a/baremaps-core/src/test/java/org/apache/baremaps/tilestore/pmtiles/PMTilesTest.java b/baremaps-core/src/test/java/org/apache/baremaps/tilestore/pmtiles/PMTilesTest.java
index 7de357cb2..fd60b1979 100644
--- a/baremaps-core/src/test/java/org/apache/baremaps/tilestore/pmtiles/PMTilesTest.java
+++ b/baremaps-core/src/test/java/org/apache/baremaps/tilestore/pmtiles/PMTilesTest.java
@@ -149,7 +149,7 @@ void decodeHeader() throws IOException {
       assertFalse(header.isClustered());
       assertEquals(header.getInternalCompression(), Compression.Gzip);
       assertEquals(header.getTileCompression(), Compression.Gzip);
-      assertEquals(header.getTileType(), TileType.Mvt);
+      assertEquals(header.getTileType(), TileType.mvt);
       assertEquals(header.getMinZoom(), 0);
       assertEquals(header.getMaxZoom(), 0);
       assertEquals(header.getMinLon(), 0);
@@ -178,7 +178,7 @@ void encodeHeader() throws IOException {
         false,
         Compression.Gzip,
         Compression.Gzip,
-        TileType.Mvt,
+        TileType.mvt,
         0,
         0,
         0,