PostgreSQL migration parameter "locale" must be specified

Question

I've been trying to set up migration in .NET, I have auto-generated migrate files, but there are some problems with it. When I try to execute this piece code:

modelBuilder
    .HasAnnotation("Npgsql:CollationDefinition:insensitive_collation", "en-u-ks-primary,en-u-ks-primary,icu,")
    .HasAnnotation("Relational:MaxIdentifierLength", 63)
    .HasAnnotation("ProductVersion", "5.0.4")
    .HasAnnotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn);

It says:
42P17: parameter "locale" must be specified.
How should I edit "en-u-ks-primary,en-u-ks-primary,icu," to fix it?

Edit: I'm using entity-framework 5.0.7