diff --git a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundDatabaseHelperTests.cs b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundDatabaseHelperTests.cs
index b50c2fb3..e9ec4a89 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundDatabaseHelperTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundDatabaseHelperTests.cs
@@ -33,11 +33,25 @@ public class InboundDatabaseHelperTests
             => throw new NotImplementedException();
     }
 
-    private static SqliteGateway SeededGateway(bool honorTokenOnOpen = true)
+    /// <summary>
+    /// Keep-alive for the shared in-memory database, rooted in a static field. It used to be a
+    /// local in the seeding helper: once the helper returned nothing referenced it, so after a GC the
+    /// Sqlite pool could reclaim the leaked connection, close the last connection and destroy the
+    /// database before the test's query ran (<c>no such table: Machine</c>). This is the same latent
+    /// flake the executor tests hit.
+    /// </summary>
+    private static readonly SqliteConnection KeepAlive = OpenKeepAlive();
+
+    private static SqliteConnection OpenKeepAlive()
     {
         var keep = new SqliteConnection("DataSource=file:movein?mode=memory&cache=shared");
-        keep.Open(); // keep-alive: shared in-memory db lives until process exit
-        using var cmd = keep.CreateCommand();
+        keep.Open(); // lives until process exit
+        return keep;
+    }
+
+    private static SqliteGateway SeededGateway(bool honorTokenOnOpen = true)
+    {
+        using var cmd = KeepAlive.CreateCommand();
         cmd.CommandText = "CREATE TABLE IF NOT EXISTS Machine(Code TEXT, SAPID TEXT); DELETE FROM Machine; INSERT INTO Machine VALUES('Z28061A','131453');";
         cmd.ExecuteNonQuery();
         return new SqliteGateway("DataSource=file:movein?mode=memory&cache=shared", honorTokenOnOpen);
diff --git a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorTests.cs b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorTests.cs
index 4d47c438..0d8a701c 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.InboundAPI.Tests/InboundScriptExecutorTests.cs
@@ -940,6 +940,13 @@ public class InboundScriptExecutorTests
         var services = new ServiceCollection();
         services.AddSingleton<IDatabaseGateway>(SeededSqliteGateway());
         using var provider = services.BuildServiceProvider();
+        // Regression guard for the old flake: force the collection the full suite used to hit during
+        // the script compile, then the pool reclaim that followed it. An unrooted keep-alive dies here
+        // deterministically ("Internal script error"); ClearAllPools only closes IDLE connections.
+        GC.Collect();
+        GC.WaitForPendingFinalizers();
+        GC.Collect();
+        SqliteConnection.ClearAllPools();
 
         var executor = new InboundScriptExecutor(
             NullLogger<InboundScriptExecutor>.Instance, provider);
@@ -1052,11 +1059,26 @@ public class InboundScriptExecutorTests
             => throw new NotImplementedException();
     }
 
-    private static SqliteGateway SeededSqliteGateway()
+    /// <summary>
+    /// Keep-alive for the shared in-memory database, rooted in a static field. It used to be a
+    /// local in the seeding helper: once the helper returned nothing referenced it, so after a GC
+    /// (likely during the script compile under a full-suite run) Microsoft.Data.Sqlite's pool
+    /// reclaimed the leaked connection, closed the last connection and destroyed the database. The
+    /// query then failed with <c>no such table: Machine</c>, which the script reported as "Internal
+    /// script error" (4 runs in 30, captured 2026-11-10).
+    /// </summary>
+    private static readonly SqliteConnection KeepAlive = OpenKeepAlive();
+
+    private static SqliteConnection OpenKeepAlive()
     {
         var keep = new SqliteConnection("DataSource=file:movein-exec?mode=memory&cache=shared");
-        keep.Open(); // keep-alive: shared in-memory db lives until process exit
-        using var cmd = keep.CreateCommand();
+        keep.Open(); // lives until process exit
+        return keep;
+    }
+
+    private static SqliteGateway SeededSqliteGateway()
+    {
+        using var cmd = KeepAlive.CreateCommand();
         cmd.CommandText = "CREATE TABLE IF NOT EXISTS Machine(Code TEXT, SAPID TEXT); DELETE FROM Machine; INSERT INTO Machine VALUES('Z28061A','131453');";
         cmd.ExecuteNonQuery();
         return new SqliteGateway("DataSource=file:movein-exec?mode=memory&cache=shared");