diff --git a/CHANGELOG.md b/CHANGELOG.md
index 31e62213f..40cd73c00 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -152,6 +152,11 @@
   Framework integration tests cover override acceptance, fallback acceptance,
   and full persistence round-trip. Tests use `@tdd_expected_fail` until the
   fix is merged. (#1100)
+- Fixed Robot Framework test mocks for ``plan correct`` dry-run and correction
+  subplan helpers to use ``container.decision_service()`` instead of the
+  non-existent ``container.resolve()``, matching corrected production code.
+  Activated regression-guard BDD scenarios for ``plan tree``, ``plan explain``,
+  and ``plan correct``.  (#647)
 - Added TDD bug-capture tests for bug #1076 — `use_action()` does not
   propagate `automation_profile` to Plan. Three Behave BDD scenarios
   (`@tdd_bug @tdd_bug_1076 @tdd_expected_fail`) verify the full precedence
diff --git a/features/container_resolve_crash.feature b/features/container_resolve_crash.feature
index d4b8e3fef..5d8055625 100644
--- a/features/container_resolve_crash.feature
+++ b/features/container_resolve_crash.feature
@@ -7,8 +7,7 @@ Feature: Container.resolve() crash in plan tree/explain/correct commands
   this class of bug because they mock get_container() with MagicMock, which
   auto-creates any attribute.
 
-  NOTE: Bug #647 appears fixed; these scenarios now run as normal
-  regression checks for correct command behavior.
+  NOTE: Bug #647 is fixed; these scenarios serve as permanent regression guards.
   `plan correct` is intentionally exercised with `--dry-run` in this
   real-container path so no live LLM execution is triggered.
 
diff --git a/robot/helper_m3_decision_validation_smoke.py b/robot/helper_m3_decision_validation_smoke.py
index a282a6d89..2b81fb245 100644
--- a/robot/helper_m3_decision_validation_smoke.py
+++ b/robot/helper_m3_decision_validation_smoke.py
@@ -21,6 +21,7 @@ if _SRC not in sys.path:
 from helpers_common import reset_global_state  # noqa: E402
 from typer.testing import CliRunner  # noqa: E402
 
+from cleveragents.application.container import Container  # noqa: E402
 from cleveragents.cli.commands.invariant import app as invariant_app  # noqa: E402
 from cleveragents.cli.commands.plan import app as plan_app  # noqa: E402
 from cleveragents.cli.commands.validation import app as validation_app  # noqa: E402
@@ -275,12 +276,12 @@ def plan_correct_dry_run() -> None:
     mock_correction_svc.request_correction.return_value = mock_request
     mock_correction_svc.analyze_impact.return_value = mock_impact
 
-    # Mock DecisionService resolved via DI container (issue #606 fix)
+    # Mock DecisionService provider on DI container (issue #606 / #647 fix)
     mock_decision_svc = MagicMock()
     mock_decision_svc.list_decisions.return_value = []
     mock_decision_svc.get_influence_edges.return_value = {}
-    mock_container = MagicMock()
-    mock_container.resolve.return_value = mock_decision_svc
+    mock_container = MagicMock(spec=Container)
+    mock_container.decision_service.return_value = mock_decision_svc
 
     with (
         patch(
diff --git a/robot/helper_m4_correction_subplan_smoke.py b/robot/helper_m4_correction_subplan_smoke.py
index ab53f00e6..586ac822d 100644
--- a/robot/helper_m4_correction_subplan_smoke.py
+++ b/robot/helper_m4_correction_subplan_smoke.py
@@ -21,6 +21,7 @@ from helpers_common import reset_global_state  # noqa: E402
 from typer.testing import CliRunner  # noqa: E402
 from ulid import ULID  # noqa: E402
 
+from cleveragents.application.container import Container  # noqa: E402
 from cleveragents.cli.commands.plan import app as plan_app  # noqa: E402
 from cleveragents.domain.models.core.correction import (  # noqa: E402
     CorrectionImpact,
@@ -115,12 +116,12 @@ def _mock_correction_service() -> MagicMock:
 
 
 def _mock_container() -> MagicMock:
-    """Create a mock DI container that resolves a stub DecisionService."""
+    """Create a mock DI container with a stub DecisionService provider."""
     mock_decision_svc = MagicMock()
     mock_decision_svc.list_decisions.return_value = []
     mock_decision_svc.get_influence_edges.return_value = {}
-    container = MagicMock()
-    container.resolve.return_value = mock_decision_svc
+    container = MagicMock(spec=Container)
+    container.decision_service.return_value = mock_decision_svc
     return container