diff --git a/src/test/java/org/jvnet/jenkins/plugins/nodelabelparameter/LabelParameterDefinitionTest.java b/src/test/java/org/jvnet/jenkins/plugins/nodelabelparameter/LabelParameterDefinitionTest.java
index 5f9c92d..dbf3b64 100644
--- a/src/test/java/org/jvnet/jenkins/plugins/nodelabelparameter/LabelParameterDefinitionTest.java
+++ b/src/test/java/org/jvnet/jenkins/plugins/nodelabelparameter/LabelParameterDefinitionTest.java
@@ -3,6 +3,7 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -14,6 +15,8 @@
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.jenkins.plugins.nodelabelparameter.node.AllNodeEligibility;
+import org.jvnet.jenkins.plugins.nodelabelparameter.node.IgnoreOfflineNodeEligibility;
 
 public class LabelParameterDefinitionTest {
 
@@ -46,6 +49,7 @@ public void testNodeParameterDefinitionDeprecated() {
         assertThat(nodeParameterDefinition.getDescription(), is(description));
         assertThat(nodeParameterDefinition.getDefaultParameterValue().getLabel(), is(defaultValue));
         assertThat(nodeParameterDefinition.getTriggerIfResult(), is(triggerIfResult));
+        assertThat(nodeParameterDefinition.getNodeEligibility(), is(instanceOf(IgnoreOfflineNodeEligibility.class)));
         assertTrue(nodeParameterDefinition.isAllNodesMatchingLabel());
     }
 
@@ -64,6 +68,7 @@ public void testNodeParameterDefinitionDeprecated3Arg() {
         assertThat(nodeParameterDefinition.getDescription(), is(description));
         assertThat(nodeParameterDefinition.getDefaultParameterValue().getLabel(), is(defaultValue));
         assertThat(nodeParameterDefinition.getTriggerIfResult(), is("allCases"));
+        assertThat(nodeParameterDefinition.getNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
         assertFalse(nodeParameterDefinition.isAllNodesMatchingLabel());
     }
 
@@ -82,12 +87,14 @@ public void testNodeParameterDefinition() {
         assertThat(nodeParameterDefinition.getDescription(), is(description));
         assertThat(nodeParameterDefinition.getDefaultParameterValue().getLabel(), is(defaultValue));
         assertThat(nodeParameterDefinition.getTriggerIfResult(), is(triggerIfResult));
+        assertThat(nodeParameterDefinition.getNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
         assertFalse(nodeParameterDefinition.isAllNodesMatchingLabel());
     }
 
     @Test
     public void testDoListNodesForAgentLabel() throws Exception {
         LabelParameterDefinition.DescriptorImpl nodeParameterDefinition = new LabelParameterDefinition.DescriptorImpl();
+        assertThat(nodeParameterDefinition.getDefaultNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
         FormValidation validation = nodeParameterDefinition.doListNodesForLabel(LABEL_NAME);
         String msg = validation.getMessage();
         assertThat(msg, allOf(containsString("Matching nodes"), containsString(agent.getNodeName())));
@@ -97,6 +104,7 @@ public void testDoListNodesForAgentLabel() throws Exception {
     public void testDoListNodesForControllerLabel() throws Exception {
         String controllerLabel = "built-in";
         LabelParameterDefinition.DescriptorImpl nodeParameterDefinition = new LabelParameterDefinition.DescriptorImpl();
+        assertThat(nodeParameterDefinition.getDefaultNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
         FormValidation validation = nodeParameterDefinition.doListNodesForLabel(controllerLabel);
         String msg = validation.getMessage();
         assertThat(msg, allOf(containsString("Matching nodes"), containsString(controllerLabel)));
@@ -106,8 +114,33 @@ public void testDoListNodesForControllerLabel() throws Exception {
     public void testDoListNodesForNonExistentLabel() throws Exception {
         String badLabel = "this-label-does-not-exist";
         LabelParameterDefinition.DescriptorImpl nodeParameterDefinition = new LabelParameterDefinition.DescriptorImpl();
+        assertThat(nodeParameterDefinition.getDefaultNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
         FormValidation validation = nodeParameterDefinition.doListNodesForLabel(badLabel);
         String msg = validation.getMessage();
         assertThat(msg, allOf(containsString("The label expression"), containsString(badLabel)));
     }
+
+    @Test
+    public void testDoListNodesForBlankLabel() throws Exception {
+        String blankLabel = "";
+        LabelParameterDefinition.DescriptorImpl nodeParameterDefinition = new LabelParameterDefinition.DescriptorImpl();
+        FormValidation validation = nodeParameterDefinition.doListNodesForLabel(blankLabel);
+        String msg = validation.getMessage();
+        assertThat(msg, containsString("a label is required"));
+    }
+
+    @Test
+    public void testDoListNodesForInvalidLabelExpression() throws Exception {
+        String invalidLabel = "a||";
+        LabelParameterDefinition.DescriptorImpl nodeParameterDefinition = new LabelParameterDefinition.DescriptorImpl();
+        assertThat(nodeParameterDefinition.getDefaultNodeEligibility(), is(instanceOf(AllNodeEligibility.class)));
+        FormValidation validation = nodeParameterDefinition.doListNodesForLabel(invalidLabel);
+        String msg = validation.getMessage();
+        assertThat(
+                msg,
+                allOf(
+                        containsString("The label expression"),
+                        containsString(invalidLabel),
+                        containsString("is not valid")));
+    }
 }