diff --git a/bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/RuleEngineImpl.java b/bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/RuleEngineImpl.java
index aeae620de67..a761d7b85d4 100644
--- a/bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/RuleEngineImpl.java
+++ b/bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/RuleEngineImpl.java
@@ -178,7 +178,7 @@ public class RuleEngineImpl implements RuleManager, RegistryChangeListener<Modul
      * The context map of a {@link Rule} is cleaned when the execution is completed. The relation is
      * {@link Rule}'s UID to Rule context map.
      */
-    private final Map<String, Map<String, Object>> contextMap = new HashMap<>();
+    private final Map<String, Map<String, Object>> contextMap = new ConcurrentHashMap<>();
 
     /**
      * This field holds reference to {@link ModuleTypeRegistry}. The {@link RuleEngineImpl} needs it to auto-map