diff --git a/src/main/java/hudson/matrix/LabelAwareAxis.java b/src/main/java/hudson/matrix/LabelAwareAxis.java
new file mode 100644
index 00000000..75a7ca1e
--- /dev/null
+++ b/src/main/java/hudson/matrix/LabelAwareAxis.java
@@ -0,0 +1,45 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2015 Jesse Glick.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package hudson.matrix;
+
+import hudson.model.Label;
+import java.util.Set;
+
+/**
+ * An axis which can control the node on which a {@link MatrixRun} may run.
+ */
+public interface LabelAwareAxis /* extends Axis */ {
+
+    /**
+     * Determines what label expression should be used to restrict execution of this combination.
+     */
+    String getAssignedLabelExpression(Combination c);
+
+    /**
+     * Determines which labels might be required for any possible values of this axis.
+     */
+    Set<Label> getLabels();
+
+}
diff --git a/src/main/java/hudson/matrix/LabelAxis.java b/src/main/java/hudson/matrix/LabelAxis.java
index bd32df00..9cdcdc84 100644
--- a/src/main/java/hudson/matrix/LabelAxis.java
+++ b/src/main/java/hudson/matrix/LabelAxis.java
@@ -37,7 +37,7 @@
  *
  * @author Kohsuke Kawaguchi
  */
-public class LabelAxis extends Axis {
+public class LabelAxis extends Axis implements LabelAwareAxis {
     @DataBoundConstructor
     public LabelAxis(String name, List<String> values) {
         super(name, values);
diff --git a/src/main/java/hudson/matrix/LabelExpAxis.java b/src/main/java/hudson/matrix/LabelExpAxis.java
index e9f18b65..920dc013 100644
--- a/src/main/java/hudson/matrix/LabelExpAxis.java
+++ b/src/main/java/hudson/matrix/LabelExpAxis.java
@@ -45,7 +45,7 @@
  *
  * @since 1.403
  */
-public class LabelExpAxis extends Axis {
+public class LabelExpAxis extends Axis implements LabelAwareAxis {
 	
     @DataBoundConstructor
     public LabelExpAxis(String name, String values) {
diff --git a/src/main/java/hudson/matrix/MatrixConfiguration.java b/src/main/java/hudson/matrix/MatrixConfiguration.java
index 6b0d2be0..32b188a8 100644
--- a/src/main/java/hudson/matrix/MatrixConfiguration.java
+++ b/src/main/java/hudson/matrix/MatrixConfiguration.java
@@ -310,7 +310,7 @@ public MatrixConfiguration asProject() {
     public Label getAssignedLabel() {
         // combine all the label axes by &&.
     	String expr;
-        String exprSlave = Util.join(combination.values(getParent().getAxes().subList(LabelAxis.class)), "&&");
+        String exprSlave = Util.join(combination.values(getParent().getAxes().subList(LabelAxis.class)), "&&"); // TODO
         String exprLabel = Util.join(combination.values(getParent().getAxes().subList(LabelExpAxis.class)), "&&");
         if(!exprSlave.equals("") && !exprLabel.equals("")){
         	expr = exprSlave + "&&" + exprLabel;
diff --git a/src/main/java/hudson/matrix/MatrixProject.java b/src/main/java/hudson/matrix/MatrixProject.java
index b383f0e4..f2ce24cb 100644
--- a/src/main/java/hudson/matrix/MatrixProject.java
+++ b/src/main/java/hudson/matrix/MatrixProject.java
@@ -782,7 +782,7 @@ public Set<JDK> getJDKs() {
      */
     public Set<Label> getLabels() {
         Set<Label> r = new HashSet<Label>();
-        for (Combination c : axes.subList(LabelAxis.class).list())
+        for (Combination c : axes.subList(LabelAxis.class).list()) // TODO
             r.add(Jenkins.getInstance().getLabel(Util.join(c.values(),"&&")));
         return r;
     }