diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/EventHintSupplier.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/EventHintSupplier.java
index 076bfc0..3ad1847 100644
--- a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/EventHintSupplier.java
+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/EventHintSupplier.java
@@ -22,5 +22,5 @@
  */
 @FunctionalInterface
 public interface EventHintSupplier {
-    String apply(Event event) throws Throwable;
+    String apply(Event event);
 }
diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/TimerChain.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/TimerChain.java
index 33c6aa3..1118568 100644
--- a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/TimerChain.java
+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/TimerChain.java
@@ -16,6 +16,7 @@
 package org.onosproject.workflow.api;
 
 import java.util.Date;
+import java.util.Objects;
 import java.util.PriorityQueue;
 import java.util.Timer;
 import java.util.TimerTask;
@@ -212,6 +213,24 @@
             return date().compareTo(target.date());
         }
 
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (!(o instanceof TimerChainTask)) {
+                return false;
+            }
+            TimerChainTask that = (TimerChainTask) o;
+
+            return this.date().equals(that.date());
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(date);
+        }
+
         /**
          * Copies timer chain task.
          * @return timer chain task