diff --git a/services/Directory/FilterLists.Directory.Domain/Aggregates/AggregateType.cs b/services/Directory/FilterLists.Directory.Domain/Aggregates/AggregateType.cs
new file mode 100644
index 000000000..e018ca840
--- /dev/null
+++ b/services/Directory/FilterLists.Directory.Domain/Aggregates/AggregateType.cs
@@ -0,0 +1,12 @@
+namespace FilterLists.Directory.Domain.Aggregates;
+
+public enum AggregateType
+{
+    FilterList,
+    Language,
+    License,
+    Maintainer,
+    Software,
+    Syntax,
+    Tag
+}
diff --git a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/Context/CommandDbContext.cs b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/Context/CommandDbContext.cs
index 391213a6f..55720239d 100644
--- a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/Context/CommandDbContext.cs
+++ b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/Context/CommandDbContext.cs
@@ -1,12 +1,19 @@
-using FilterLists.Directory.Domain.Aggregates.FilterLists;
+using FilterLists.Directory.Domain.Aggregates;
+using FilterLists.Directory.Domain.Aggregates.FilterLists;
 using FilterLists.Directory.Domain.Aggregates.Licenses;
 using FilterLists.Directory.Infrastructure.Persistence.Commands.EntityTypeConfigurations;
 using Microsoft.EntityFrameworkCore;
+using Npgsql;
 
 namespace FilterLists.Directory.Infrastructure.Persistence.Commands.Context;
 
 internal class CommandDbContext : DbContext, ICommandContext
 {
+    static CommandDbContext()
+    {
+        NpgsqlConnection.GlobalTypeMapper.MapEnum<AggregateType>();
+    }
+
     public CommandDbContext(DbContextOptions<CommandDbContext> options) : base(options)
     {
     }
@@ -18,5 +25,6 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
         modelBuilder.ApplyConfigurationsFromAssembly(GetType().Assembly,
             type => type.Namespace == typeof(FilterListTypeConfiguration).Namespace);
+        modelBuilder.HasPostgresEnum<AggregateType>();
     }
 }
diff --git a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/EntityTypeConfigurations/ChangeTypeConfiguration.cs b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/EntityTypeConfigurations/ChangeTypeConfiguration.cs
index b8b62c854..ef1121858 100644
--- a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/EntityTypeConfigurations/ChangeTypeConfiguration.cs
+++ b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Commands/EntityTypeConfigurations/ChangeTypeConfiguration.cs
@@ -1,4 +1,7 @@
-using FilterLists.Directory.Domain.Aggregates.Changes;
+using System.Globalization;
+using EFCore.NamingConventions.Internal;
+using FilterLists.Directory.Domain.Aggregates;
+using FilterLists.Directory.Domain.Aggregates.Changes;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
@@ -8,6 +11,12 @@ internal class ChangeTypeConfiguration : IEntityTypeConfiguration<Change>
 {
     public virtual void Configure(EntityTypeBuilder<Change> builder)
     {
+        // TODO: register and resolve INameRewriter
+        var nr = new SnakeCaseNameRewriter(CultureInfo.InvariantCulture);
         builder.Property<int>(nameof(Queries.Entities.Change.Id));
+
+        // TODO: TDiscriminator should really be AggregateType rather than string but needs name rewriting
+        builder.HasDiscriminator<string>(nr.RewriteName(nameof(Queries.Entities.Change.AggregateType)))
+            .HasValue<FilterListChange>(nr.RewriteName(nameof(AggregateType.FilterList)));
     }
 }
diff --git a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Context/QueryDbContext.cs b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Context/QueryDbContext.cs
index 34de1085f..1714787e5 100644
--- a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Context/QueryDbContext.cs
+++ b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Context/QueryDbContext.cs
@@ -1,10 +1,17 @@
-using FilterLists.Directory.Infrastructure.Persistence.Queries.Entities;
+using FilterLists.Directory.Domain.Aggregates;
+using FilterLists.Directory.Infrastructure.Persistence.Queries.Entities;
 using Microsoft.EntityFrameworkCore;
+using Npgsql;
 
 namespace FilterLists.Directory.Infrastructure.Persistence.Queries.Context;
 
 public class QueryDbContext : DbContext
 {
+    static QueryDbContext()
+    {
+        NpgsqlConnection.GlobalTypeMapper.MapEnum<AggregateType>();
+    }
+
     public QueryDbContext(DbContextOptions<QueryDbContext> options) : base(options)
     {
     }
@@ -34,5 +41,6 @@ protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
         modelBuilder.ApplyConfigurationsFromAssembly(GetType().Assembly,
             type => type.Namespace == typeof(FilterListTypeConfiguration).Namespace);
+        modelBuilder.HasPostgresEnum<AggregateType>();
     }
 }
diff --git a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Entities/Change.cs b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Entities/Change.cs
index 79a4be35c..a7baa5a26 100644
--- a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Entities/Change.cs
+++ b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/Queries/Entities/Change.cs
@@ -1,6 +1,7 @@
 using System.Globalization;
 using System.Text.Json;
 using EFCore.NamingConventions.Internal;
+using FilterLists.Directory.Domain.Aggregates;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
 
@@ -16,7 +17,7 @@ public record Change
     public string? RejectedReason { get; private init; }
     public JsonDocument? AggregateBefore { get; private init; }
     public JsonDocument? AggregateAfter { get; private init; }
-    public string? AggregateType { get; private init; }
+    public AggregateType? AggregateType { get; private init; }
     public int? FilterListId { get; private init; }
     public FilterList? FilterList { get; }
     public string? LanguageIso6391 { get; private init; }
@@ -33,17 +34,6 @@ public record Change
     public Tag? Tag { get; }
 }
 
-internal enum AggregateType
-{
-    FilterList,
-    Language,
-    License,
-    Maintainer,
-    Software,
-    Syntax,
-    Tag
-}
-
 internal class UpdateConfiguration : IEntityTypeConfiguration<Change>
 {
     public virtual void Configure(EntityTypeBuilder<Change> builder)
@@ -54,16 +44,17 @@ public virtual void Configure(EntityTypeBuilder<Change> builder)
 
         static string BuildComputedAggregateTypeSql()
         {
-            var nameRewriter = new SnakeCaseNameRewriter(CultureInfo.InvariantCulture);
+            // TODO: register and resolve INameRewriter
+            var nr = new SnakeCaseNameRewriter(CultureInfo.InvariantCulture);
             return $@"
                 CASE 
-                    WHEN {nameRewriter.RewriteName(nameof(Change.FilterListId))} IS NOT NULL THEN '{AggregateType.FilterList}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.LanguageIso6391))} IS NOT NULL THEN '{AggregateType.Language}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.LicenseId))} IS NOT NULL THEN '{AggregateType.License}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.MaintainerId))} IS NOT NULL THEN '{AggregateType.Maintainer}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.SoftwareId))} IS NOT NULL THEN '{AggregateType.Software}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.SyntaxId))} IS NOT NULL THEN '{AggregateType.Syntax}'
-                    WHEN {nameRewriter.RewriteName(nameof(Change.TagId))} IS NOT NULL THEN '{AggregateType.Tag}'
+                    WHEN {nr.RewriteName(nameof(Change.FilterListId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.FilterList))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.LanguageIso6391))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.Language))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.LicenseId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.License))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.MaintainerId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.Maintainer))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.SoftwareId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.Software))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.SyntaxId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.Syntax))}'::{nr.RewriteName(nameof(AggregateType))}
+                    WHEN {nr.RewriteName(nameof(Change.TagId))} IS NOT NULL THEN '{nr.RewriteName(nameof(AggregateType.Tag))}'::{nr.RewriteName(nameof(AggregateType))}
                     ELSE NULL
                 END";
         }
diff --git a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/SeedExtensions.cs b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/SeedExtensions.cs
index 472dba893..0f5c5eb0c 100644
--- a/services/Directory/FilterLists.Directory.Infrastructure/Persistence/SeedExtensions.cs
+++ b/services/Directory/FilterLists.Directory.Infrastructure/Persistence/SeedExtensions.cs
@@ -5,6 +5,7 @@
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Npgsql;
 
 namespace FilterLists.Directory.Infrastructure.Persistence;
 
@@ -15,6 +16,9 @@ public static async Task MigrateAsync(this IHost host)
         using var scope = host.Services.CreateScope();
         var db = scope.ServiceProvider.GetRequiredService<QueryDbContext>();
         await db.Database.MigrateAsync();
+        await using var conn = (NpgsqlConnection)db.Database.GetDbConnection();
+        await conn.OpenAsync();
+        conn.ReloadTypes();
     }
 }