diff --git a/src/OpenIddict.EntityFramework/Configurations/OpenIddictEntityFrameworkSessionConfiguration.cs b/src/OpenIddict.EntityFramework/Configurations/OpenIddictEntityFrameworkSessionConfiguration.cs
index 01924a1d..0acaf704 100644
--- a/src/OpenIddict.EntityFramework/Configurations/OpenIddictEntityFrameworkSessionConfiguration.cs
+++ b/src/OpenIddict.EntityFramework/Configurations/OpenIddictEntityFrameworkSessionConfiguration.cs
@@ -58,9 +58,6 @@ public sealed class OpenIddictEntityFrameworkSessionConfiguration<
         Property(static session => session.LoginId)
             .HasMaxLength(100);
 
-        // Warning: the index on the LoginId property MUST NOT be declared as
-        // a unique index, as Entity Framework 6.x doesn't support creating indexes
-        // with null-friendly WHERE conditions, unlike Entity Framework Core.
         HasIndex(static session => session.LoginId);
 
         Property(static session => session.Status)
diff --git a/src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreSessionConfiguration.cs b/src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreSessionConfiguration.cs
index e5e5e785..39697fbe 100644
--- a/src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreSessionConfiguration.cs
+++ b/src/OpenIddict.EntityFrameworkCore/Configurations/OpenIddictEntityFrameworkCoreSessionConfiguration.cs
@@ -60,8 +60,7 @@ public sealed class OpenIddictEntityFrameworkCoreSessionConfiguration<
         builder.Property(static session => session.LoginId)
                .HasMaxLength(100);
 
-        builder.HasIndex(static session => session.LoginId)
-               .IsUnique();
+        builder.HasIndex(static session => session.LoginId);
 
         builder.Property(static session => session.Status)
                .HasMaxLength(50);