Index: src/main/java/org/apache/maven/project/ModelUtils.java
===================================================================
--- src/main/java/org/apache/maven/project/ModelUtils.java	(revision 739329)
+++ src/main/java/org/apache/maven/project/ModelUtils.java	(working copy)
@@ -98,7 +98,10 @@
                 int idx = normalized.indexOf( currentPlugin );
                 Plugin firstPlugin = (Plugin) normalized.get( idx );
 
-                mergePluginDefinitions( firstPlugin, currentPlugin, false );
+                // MNG-3719: merge currentPlugin with firstPlugin as parent,
+                // then use updated currentPlugin as new parent
+                mergePluginDefinitions( currentPlugin, firstPlugin, false );
+                normalized.set(idx, currentPlugin);
             }
             else
             {