diff --git a/core/api/src/main/java/org/onosproject/net/config/basics/SubjectFactories.java b/core/api/src/main/java/org/onosproject/net/config/basics/SubjectFactories.java
index 1eda703..aeaf84d 100644
--- a/core/api/src/main/java/org/onosproject/net/config/basics/SubjectFactories.java
+++ b/core/api/src/main/java/org/onosproject/net/config/basics/SubjectFactories.java
@@ -140,7 +140,7 @@
      *
      * @param service core service reference
      */
-    public static void setCoreService(CoreService service) {
+    public static synchronized void setCoreService(CoreService service) {
         coreService = service;
     }
 
diff --git a/core/api/src/main/java/org/onosproject/net/intent/Intent.java b/core/api/src/main/java/org/onosproject/net/intent/Intent.java
index 7a541e7..b7af54f 100644
--- a/core/api/src/main/java/org/onosproject/net/intent/Intent.java
+++ b/core/api/src/main/java/org/onosproject/net/intent/Intent.java
@@ -48,6 +48,7 @@
     private final ResourceGroup resourceGroup;
 
     private static IdGenerator idGenerator;
+    private static final Object ID_GENERATOR_LOCK = new Object();
 
     /**
      * Constructor for serializer.
@@ -248,8 +249,10 @@
      * @param newIdGenerator id generator
      */
     public static void bindIdGenerator(IdGenerator newIdGenerator) {
-        checkState(idGenerator == null, "Id generator is already bound.");
-        idGenerator = checkNotNull(newIdGenerator);
+        synchronized (ID_GENERATOR_LOCK) {
+            checkState(idGenerator == null, "Id generator is already bound.");
+            idGenerator = checkNotNull(newIdGenerator);
+        }
     }
 
     /**
@@ -260,8 +263,10 @@
      * @param oldIdGenerator the current id generator
      */
     public static void unbindIdGenerator(IdGenerator oldIdGenerator) {
-        if (idGenerator == oldIdGenerator) {
-            idGenerator = null;
+        synchronized (ID_GENERATOR_LOCK) {
+            if (idGenerator == oldIdGenerator) {
+                idGenerator = null;
+            }
         }
     }