diff --git a/src/EFCore.PG/Infrastructure/Internal/NpgsqlOptionsExtension.cs b/src/EFCore.PG/Infrastructure/Internal/NpgsqlOptionsExtension.cs
index 1ed164bb4..bdce70697 100644
--- a/src/EFCore.PG/Infrastructure/Internal/NpgsqlOptionsExtension.cs
+++ b/src/EFCore.PG/Infrastructure/Internal/NpgsqlOptionsExtension.cs
@@ -145,7 +145,8 @@ public override RelationalOptionsExtension WithConnectionString(string? connecti
     /// <inheritdoc />
     public override RelationalOptionsExtension WithConnection(DbConnection? connection)
     {
-        var clone = (NpgsqlOptionsExtension)base.WithConnection(connection);
+        var clone = (NpgsqlOptionsExtension)base.WithConnection(connection)
+            .WithConnectionString(connection?.ConnectionString);
 
         clone.DataSource = null;