diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.IntegrationTests/SqlServerReadTests.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.IntegrationTests/SqlServerReadTests.cs
index ebf2d212..ff6271bc 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.IntegrationTests/SqlServerReadTests.cs
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Sql.IntegrationTests/SqlServerReadTests.cs
@@ -58,6 +58,64 @@ public sealed class SqlServerReadTests
         driver.GetHostStatuses().ShouldHaveSingleItem().State.ShouldBe(HostState.Running);
     }
 
+    // ---- R06:S-1: the row cap, on real T-SQL ----
+
+    /// <summary>
+    ///     A where-pair selector pointed at an events table (40 rows for one station) used to pull every
+    ///     matching row on every poll. The plan now emits <c>SELECT TOP (2) …</c> — proven valid T-SQL here —
+    ///     and the second row makes the tag publish <c>BadConfigurationError</c> while the driver stays
+    ///     Healthy (the server answered). The positive control: a station with exactly one row reads Good
+    ///     through the same capped statement.
+    /// </summary>
+    [Fact]
+    public async Task ReadAsync_realSqlServer_anAmbiguousSelectorIsRowCappedToAConfigurationError()
+    {
+        SkipUnlessLive();
+        const string table = "RowCapEvents";
+
+        await using (var arrange = await _sql.OpenInspectionConnectionAsync())
+        {
+            await using var command = arrange.CreateCommand();
+            command.CommandText = string.Create(CultureInfo.InvariantCulture, $"""
+                IF OBJECT_ID(N'{SqlPollServerFixture.Schema}.{table}') IS NOT NULL DROP TABLE {SqlPollServerFixture.Schema}.{table};
+                CREATE TABLE {SqlPollServerFixture.Schema}.{table} (
+                    {SqlPollServerFixture.WideRowSelectorColumn} int NOT NULL,
+                    oven_temp float NULL,
+                    {SqlPollServerFixture.TimestampColumn} datetime2 NOT NULL);
+                INSERT INTO {SqlPollServerFixture.Schema}.{table} VALUES (1, 21.5, '2026-07-24T10:00:00');
+                DECLARE @i int = 0;
+                WHILE @i < 40
+                BEGIN
+                    INSERT INTO {SqlPollServerFixture.Schema}.{table} VALUES (7, @i, DATEADD(second, @i, '2026-07-24T10:00:00'));
+                    SET @i += 1;
+                END
+                """);
+            await command.ExecuteNonQueryAsync(TestContext.Current.CancellationToken);
+        }
+
+        try
+        {
+            await using var driver = await StartAsync(
+                WideRowWhere("Sql/Events/Ambiguous", "oven_temp", "7", table),
+                WideRowWhere("Sql/Events/Clean", "oven_temp", "1", table));
+
+            var snapshots = await driver.ReadAsync(
+                ["Sql/Events/Ambiguous", "Sql/Events/Clean"], TestContext.Current.CancellationToken);
+
+            snapshots[0].StatusCode.ShouldBe(SqlStatusCodes.BadConfigurationError);
+            snapshots[1].StatusCode.ShouldBe(SqlStatusCodes.Good);
+            Convert.ToDouble(snapshots[1].Value).ShouldBe(21.5);
+            driver.GetHealth().State.ShouldBe(DriverState.Healthy);
+        }
+        finally
+        {
+            await using var cleanup = await _sql.OpenInspectionConnectionAsync();
+            await using var drop = cleanup.CreateCommand();
+            drop.CommandText = $"DROP TABLE IF EXISTS {SqlPollServerFixture.Schema}.{table}";
+            await drop.ExecuteNonQueryAsync(CancellationToken.None);
+        }
+    }
+
     // ---- key-value model ----
 
     /// <summary>The plan's headline case: a seeded key-value row round-trips as a Good snapshot.</summary>