diff --git a/Lip.Tests/PackageManifestTests.cs b/Lip.Tests/PackageManifestTests.cs
index 4710334..514c93f 100644
--- a/Lip.Tests/PackageManifestTests.cs
+++ b/Lip.Tests/PackageManifestTests.cs
@@ -399,4 +399,29 @@ public void FromBytes_InvalidVersion_ThrowsArgumentException()
 
         Assert.Throws<ArgumentException>("value", () => PackageManifest.FromBytes(bytes));
     }
+
+    [Fact]
+    public void ToBytes_MinimumInput_Serialized()
+    {
+        var manifest = new PackageManifest
+        {
+            FormatVersion = 3,
+            FormatUuid = "289f771f-2c9a-4d73-9f3f-8492495a924d",
+            Tooth = "",
+            Version = "1.0.0"
+        };
+
+        byte[] bytes = manifest.ToBytes();
+
+        string json = Encoding.UTF8.GetString(bytes);
+
+        Assert.Equal("""
+            {
+                "format_version": 3,
+                "format_uuid": "289f771f-2c9a-4d73-9f3f-8492495a924d",
+                "tooth": "",
+                "version": "1.0.0"
+            }
+            """, json);
+    }
 }
diff --git a/Lip/PackageManifest.cs b/Lip/PackageManifest.cs
index 5e53d58..eb4a03a 100644
--- a/Lip/PackageManifest.cs
+++ b/Lip/PackageManifest.cs
@@ -216,6 +216,8 @@ public record VariantType
     private static readonly JsonSerializerOptions s_jsonSerializerOptions = new()
     {
         AllowTrailingCommas = true,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+        IndentSize = 4,
         ReadCommentHandling = JsonCommentHandling.Skip,
         WriteIndented = true,
     };
@@ -274,4 +276,10 @@ public required string Version
 
         return manifest;
     }
+
+    public byte[] ToBytes()
+    {
+        byte[] bytes = JsonSerializer.SerializeToUtf8Bytes(this, s_jsonSerializerOptions);
+        return bytes;
+    }
 }