diff --git a/pronote_sync/pipeline/run.py b/pronote_sync/pipeline/run.py
index 4c873e0..02fe79d 100644
--- a/pronote_sync/pipeline/run.py
+++ b/pronote_sync/pipeline/run.py
@@ -126,6 +126,8 @@ class PipelineRunner:
         :rtype: PipelineRunner
         """
         effective_dry_run = settings.app.dry_run if dry_run is None else dry_run
+        if effective_dry_run and settings.pronote.auth_mode == "qr_token":
+            raise ValueError("Le mode qr_token n'est pas compatible avec le dry-run.")
         persistence_enabled = not effective_dry_run
         theoretical_provider = get_theoretical_provider(
             settings.app.theoretical_agenda_path,
diff --git a/tests/integration/test_pipeline_runner.py b/tests/integration/test_pipeline_runner.py
index 1eb830b..18a5e48 100644
--- a/tests/integration/test_pipeline_runner.py
+++ b/tests/integration/test_pipeline_runner.py
@@ -428,6 +428,47 @@ def test_from_settings_password_mode_passes_auth_state_none(
     assert constructed[0][1] is None
 
 
+def test_from_settings_rejects_qr_token_dry_run_before_constructing_pronote_client(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """QR-token dry-run fails before authentication or data dependencies are created."""
+    import pronote_sync.pipeline.run as run_module
+
+    qr_pin_sentinel = "qr-pin-must-not-appear"
+    constructed: list[object] = []
+
+    class FailingClient:
+        """Pronote client sentinel that makes unexpected construction explicit."""
+
+        def __init__(self, settings: PronoteSettings, *, auth_state: object) -> None:
+            """Record and reject any unexpected client construction.
+
+            :param settings: Pronote settings supplied by the composition root.
+            :param auth_state: Authentication state supplied by the composition root.
+            """
+            del settings, auth_state
+            constructed.append(object())
+            raise AssertionError("PronoteClient must not be constructed for QR-token dry-run")
+
+    monkeypatch.setattr(run_module, "PronoteClient", FailingClient)
+
+    with pytest.raises(ValueError) as exc_info:
+        PipelineRunner.from_settings(
+            Settings(
+                app=AppSettings(dry_run=True),
+                pronote=PronoteSettings(
+                    auth_mode="qr_token",
+                    qr_pin=SecretStr(qr_pin_sentinel),
+                ),
+            )
+        )
+
+    assert "qr_token" in str(exc_info.value)
+    assert "dry-run" in str(exc_info.value)
+    assert qr_pin_sentinel not in str(exc_info.value)
+    assert constructed == []
+
+
 def test_from_settings_qr_token_mode_passes_auth_state_instance(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None: