diff --git a/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/converter/ListWorkflowDefinitionConverter.java b/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/converter/ListWorkflowDefinitionConverter.java
index 675d3d553..91a32b73e 100644
--- a/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/converter/ListWorkflowDefinitionConverter.java
+++ b/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/converter/ListWorkflowDefinitionConverter.java
@@ -37,9 +37,7 @@ public ListWorkflowDefinitionResponse convert(AbstractWorkflowDefinition<? exten
     }
     for (Entry<String, List<String>> entry : definition.getAllowedTransitions().entrySet()) {
       State state = states.get(entry.getKey());
-      for(String targetState : entry.getValue()) {
-        state.transitions.add(targetState);
-      }
+      state.transitions.addAll(entry.getValue());
     }
     for (Entry<String, WorkflowState> entry : definition.getFailureTransitions().entrySet()) {
       State state = states.get(entry.getKey());
diff --git a/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/msg/ListWorkflowDefinitionResponse.java b/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/msg/ListWorkflowDefinitionResponse.java
index 1798f480f..d49541ed8 100644
--- a/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/msg/ListWorkflowDefinitionResponse.java
+++ b/nflow-rest-api-common/src/main/java/io/nflow/rest/v1/msg/ListWorkflowDefinitionResponse.java
@@ -64,7 +64,7 @@ public static class TransitionDelays extends ModelObject {
 
   }
 
-  public static class Signal {
+  public static class Signal extends ModelObject {
 
     @ApiModelProperty(value = "Signal value", required = true)
     public int value;