diff --git a/projectapi/src/org/netbeans/modules/projectapi/LazyLookupProviders.java b/projectapi/src/org/netbeans/modules/projectapi/LazyLookupProviders.java
--- a/projectapi/src/org/netbeans/modules/projectapi/LazyLookupProviders.java
+++ b/projectapi/src/org/netbeans/modules/projectapi/LazyLookupProviders.java
@@ -42,6 +42,8 @@
 
 package org.netbeans.modules.projectapi;
 
+import java.lang.ref.Reference;
+import java.lang.ref.WeakReference;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
@@ -83,9 +85,15 @@
      */
     public static LookupProvider forProjectServiceProvider(final Map<String,Object> attrs) throws ClassNotFoundException {
         return new LookupProvider() {
+            private final Map<Lookup,Reference<Lookup>> lkps = Collections.synchronizedMap(new WeakHashMap<Lookup, Reference<Lookup>>());
             @Override
             public Lookup createAdditionalLookup(final Lookup lkp) {
-                final Lookup result =  new ProxyLookup() {
+                Reference<Lookup> resRef = lkps.get(lkp);
+                Lookup result;
+                if (resRef != null && (result=resRef.get()) != null) {
+                    return result;
+                }
+                result =  new ProxyLookup() {
                     Collection<String> serviceNames = Arrays.asList(((String) attrs.get("service")).split(",")); // NOI18N
                     final ThreadLocal<Boolean> insideBeforeLookup = new ThreadLocal<Boolean>(); // #212862
                     final Object LOCK = new Object();
@@ -138,14 +146,27 @@
                         }
                     }
                 };
-                LOG.log(
-                    Level.FINE,
-                    "Additional lookup created: {0} service class: {1} for base lookup: {2}",   //NOI18N
-                    new Object[]{
-                        System.identityHashCode(result),
-                        attrs.get("class"),
-                        System.identityHashCode(lkp)
-                    });
+                boolean created = false;
+                synchronized (lkps) {
+                    resRef = lkps.get(lkp);
+                    final Lookup tmp;
+                    if (resRef == null || (tmp = resRef.get()) == null) {
+                        lkps.put(lkp, new WeakReference<Lookup>(result));
+                        created = true;
+                    } else {
+                        result = tmp;
+                    }
+                }
+                if (created) {
+                    LOG.log(
+                        Level.FINE,
+                        "Additional lookup created: {0} service class: {1} for base lookup: {2}",   //NOI18N
+                        new Object[]{
+                            System.identityHashCode(result),
+                            attrs.get("class"),
+                            System.identityHashCode(lkp)
+                        });
+                }
                 return result;
             }