diff --git a/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/Attribute.java b/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/Attribute.java
index 7a759c8c48..0e7a9b721f 100644
--- a/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/Attribute.java
+++ b/pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/xpath/Attribute.java
@@ -6,8 +6,8 @@ package net.sourceforge.pmd.lang.ast.xpath;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -20,7 +20,7 @@ public class Attribute {
 
 
     private static final Logger LOG = Logger.getLogger(Attribute.class.getName());
-    private static final Map<String, Boolean> DETECTED_DEPRECATED_ATTRIBUTES = new ConcurrentHashMap<>();
+    private static final ConcurrentMap<String, Boolean> DETECTED_DEPRECATED_ATTRIBUTES = new ConcurrentHashMap<>();
 
 
     private static final Object[] EMPTY_OBJ_ARRAY = new Object[0];
@@ -48,14 +48,14 @@ public class Attribute {
             return value;
         }
 
-        if (method.isAnnotationPresent(Deprecated.class) && LOG.isLoggable(Level.WARNING) && !DETECTED_DEPRECATED_ATTRIBUTES.containsKey(getLoggableAttributeName())) {
-            DETECTED_DEPRECATED_ATTRIBUTES.put(getLoggableAttributeName(), Boolean.TRUE);
+        if (method.isAnnotationPresent(Deprecated.class) && LOG.isLoggable(Level.WARNING)
+                && DETECTED_DEPRECATED_ATTRIBUTES.putIfAbsent(getLoggableAttributeName(), Boolean.TRUE) == null) {
             LOG.warning("Use of deprecated attribute '" + getLoggableAttributeName() + "' in xpath query");
         }
 
         // this lazy loading reduces calls to Method.invoke() by about 90%
         try {
-            return method.invoke(parent, EMPTY_OBJ_ARRAY);
+            return value = method.invoke(parent, EMPTY_OBJ_ARRAY);
         } catch (IllegalAccessException | InvocationTargetException iae) {
             iae.printStackTrace();
         }