diff --git a/csaxs_bec/devices/epics/mcs_card/mcs_card_csaxs.py b/csaxs_bec/devices/epics/mcs_card/mcs_card_csaxs.py
index 85c0dcd..0ae2b15 100644
--- a/csaxs_bec/devices/epics/mcs_card/mcs_card_csaxs.py
+++ b/csaxs_bec/devices/epics/mcs_card/mcs_card_csaxs.py
@@ -68,13 +68,14 @@ def suppress_mca_callbacks(mcs_card: MCSCard, restore_after_timeout: None | floa
             clear the suppression after the specified time. If None, the original state
             is not restored.
     """
-    mcs_card._omit_mca_callbacks.set()  # pylint: disable=protected-access
-    try:
-        yield
-    finally:
-        if restore_after_timeout is not None:
-            time.sleep(restore_after_timeout)
-            mcs_card._omit_mca_callbacks.clear()  # pylint: disable=protected-access
+    with mcs_card._rlock:
+        mcs_card._omit_mca_callbacks.set()  # pylint: disable=protected-access
+        try:
+            yield
+        finally:
+            if restore_after_timeout is not None:
+                time.sleep(restore_after_timeout)
+                mcs_card._omit_mca_callbacks.clear()  # pylint: disable=protected-access
 
 
 if TYPE_CHECKING:  # pragma: no cover