diff --git a/src/Database.Actions/Database.Actions.csproj b/src/Database.Actions/Database.Actions.csproj
index 8e5428546d3093e20e66d27d12e85ade3c136733..36cc1f2e0e14c7c4875522adc7f6f06dc446a8e1 100644
--- a/src/Database.Actions/Database.Actions.csproj
+++ b/src/Database.Actions/Database.Actions.csproj
@@ -4,7 +4,7 @@
 		<RootNamespace>Coscine.Database.Actions</RootNamespace>
 		<AssemblyName>Coscine.Database.Actions</AssemblyName>
 		<TargetFramework>net6.0</TargetFramework>
-		<Version>2.19.0</Version>
+		<Version>2.19.1</Version>
 	</PropertyGroup>
 
 	<ItemGroup>
diff --git a/src/Database.Tests/Database.Tests.csproj b/src/Database.Tests/Database.Tests.csproj
index 61e432f0331f32afe5cecedf77e8806490b0dd65..2633397a5dc7ad6f569b45dd7fbc9690ad66b1b1 100644
--- a/src/Database.Tests/Database.Tests.csproj
+++ b/src/Database.Tests/Database.Tests.csproj
@@ -5,7 +5,7 @@
 		<AssemblyName>Coscine.Database.Tests</AssemblyName>
 		<TargetFramework>net6.0</TargetFramework>
 		<GenerateAssemblyInfo>false</GenerateAssemblyInfo>
-		<Version>2.19.0</Version>
+		<Version>2.19.1</Version>
 	</PropertyGroup>
 
 	<ItemGroup>
diff --git a/src/Database/Database.csproj b/src/Database/Database.csproj
index 3e02f92cec0f034732d6ce58f95219fac017a93f..8d71827d2b169bfe65f766d8aa297d3c1048d3ac 100644
--- a/src/Database/Database.csproj
+++ b/src/Database/Database.csproj
@@ -4,7 +4,7 @@
 		<RootNamespace>Coscine.Database</RootNamespace>
 		<AssemblyName>Coscine.Database</AssemblyName>
 		<TargetFramework>net6.0</TargetFramework>
-		<Version>2.19.0</Version>
+		<Version>2.19.1</Version>
 	</PropertyGroup>
 	
 	<PropertyGroup>
diff --git a/src/Scaffolding/DataModel/Model.cs b/src/Scaffolding/DataModel/Model.cs
index 0c8c482965430c8bfef3229ce6bc2abe038c3f1f..1b3b25146d54c80f47638b1b4c88125e61646f10 100644
--- a/src/Scaffolding/DataModel/Model.cs
+++ b/src/Scaffolding/DataModel/Model.cs
@@ -409,6 +409,9 @@ namespace Coscine.Database.DataModel
             {
                 entity.HasKey(e => e.RelationId);
 
+                entity.HasIndex(e => new { e.ProjectId, e.ResourceTypeId }, "ProjectIdResourceTypeId")
+                    .IsUnique();
+
                 entity.Property(e => e.RelationId).HasDefaultValueSql("(newid())");
 
                 entity.Property(e => e.MaxQuota).HasDefaultValueSql("(N'0')");
diff --git a/src/Scaffolding/Scaffolding.csproj b/src/Scaffolding/Scaffolding.csproj
index 1014b6579c2a7c29fab5d36303f27e6deaf7e21f..f5b524d87dee972321556b8c1bef9decf2fe1c57 100644
--- a/src/Scaffolding/Scaffolding.csproj
+++ b/src/Scaffolding/Scaffolding.csproj
@@ -3,7 +3,7 @@
 		<RootNamespace>Coscine.Database</RootNamespace>
 		<AssemblyName>Coscine.Database.Scaffolding</AssemblyName>
 		<TargetFramework>net6.0</TargetFramework>
-		<Version>2.19.0</Version>
+		<Version>2.19.1</Version>
 	</PropertyGroup>
 	
 	<ItemGroup>