diff --git a/core/src/main/java/hudson/matrix/MatrixRun.java b/core/src/main/java/hudson/matrix/MatrixRun.java
index 3655720a1f9cc1843af1148d7d34ee084988cf8b..4177ce5a8b3b8b0c4a4a16b4d323d90dfedc980e 100644
--- a/core/src/main/java/hudson/matrix/MatrixRun.java
+++ b/core/src/main/java/hudson/matrix/MatrixRun.java
@@ -98,8 +98,10 @@ public class MatrixRun extends Build<MatrixConfiguration,MatrixRun> {
 
     @Override
     public Map<String,String> getBuildVariables() {
+        Map<String,String> r = super.getBuildVariables();
         // pick up user axes
-        return new HashMap<String,String>(getParent().getCombination());
+        r.putAll(getParent().getCombination());
+        return r;
     }
 
     /**
diff --git a/core/src/main/java/hudson/model/AbstractBuild.java b/core/src/main/java/hudson/model/AbstractBuild.java
index 0ce8b3250352fa0de874d343199e910743afb195..233559564b7c295482a120a6ba69df09d69de4d3 100644
--- a/core/src/main/java/hudson/model/AbstractBuild.java
+++ b/core/src/main/java/hudson/model/AbstractBuild.java
@@ -45,6 +45,7 @@ import hudson.tasks.test.AbstractTestResultAction;
 import hudson.util.AdaptedIterator;
 import hudson.util.Iterators;
 import hudson.util.VariableResolver;
+import hudson.util.VariableResolver.ByMap;
 import org.kohsuke.stapler.Stapler;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
@@ -451,10 +452,24 @@ public abstract class AbstractBuild<P extends AbstractProject<P,R>,R extends Abs
      * {@link Builder}s to decide whether it wants to recognize the values
      * or how to use them.
      *
-     * ugly ugly hack.
+     * <p>
+     * This also includes build parameters if a build is parameterized.
+     *
+     * @return
+     *      The returned map is mutable so that subtypes can put more values.
      */
     public Map<String,String> getBuildVariables() {
-        return Collections.emptyMap();
+        Map<String,String> r = new HashMap<String, String>();
+
+        ParametersAction parameters = getAction(ParametersAction.class);
+        if(parameters!=null) {
+            // this is a rather round about way of doing this...
+            for (ParameterValue p : parameters) {
+                String v = p.createVariableResolver(this).resolve(p.getName());
+                if(v!=null) r.put(p.getName(),v);
+            }
+        }
+        return r;
     }
 
     /**
diff --git a/core/src/main/java/hudson/model/ParametersAction.java b/core/src/main/java/hudson/model/ParametersAction.java
index 28d1a6c87722377e2816b02731163633715c46d3..511c8aaee386565d32591f259290c1de7338a349 100644
--- a/core/src/main/java/hudson/model/ParametersAction.java
+++ b/core/src/main/java/hudson/model/ParametersAction.java
@@ -25,6 +25,7 @@ package hudson.model;
 
 import hudson.Util;
 import hudson.tasks.BuildWrapper;
+import hudson.tasks.BuildStep;
 import hudson.util.VariableResolver;
 
 import java.util.Collection;
@@ -70,6 +71,9 @@ public class ParametersAction implements Action, Iterable<ParameterValue> {
 
     /**
      * Creates an {@link VariableResolver} that aggregates all the parameters.
+     *
+     * <p>
+     * If you are a {@link BuildStep}, most likely you should call {@link AbstractBuild#getBuildVariableResolver()}. 
      */
     public VariableResolver<String> createVariableResolver(AbstractBuild<?,?> build) {
         VariableResolver[] resolvers = new VariableResolver[parameters.size()+1];
diff --git a/core/src/main/java/hudson/tasks/Ant.java b/core/src/main/java/hudson/tasks/Ant.java
index da64cd1f47f44994c6ac8e71507f0605db6803bd..0e87c698ccbfb7a4e88812721fc05890f39668fc 100644
--- a/core/src/main/java/hudson/tasks/Ant.java
+++ b/core/src/main/java/hudson/tasks/Ant.java
@@ -167,10 +167,7 @@ public class Ant extends Builder {
         args.addKeyValuePairs("-D",build.getBuildVariables());
 
         VariableResolver<String> vr = build.getBuildVariableResolver();
-        ParametersAction parameters = build.getAction(ParametersAction.class);
-        if(parameters!=null)
-            vr = parameters.createVariableResolver(build);
-        
+
         args.addKeyValuePairsFromPropertyString("-D",properties,vr);
 
         args.addTokenized(Util.replaceMacro(targets,vr).replaceAll("[\t\r\n]+"," "));
diff --git a/core/src/main/java/hudson/tasks/Maven.java b/core/src/main/java/hudson/tasks/Maven.java
index 3da66e107d21aeb7b7a0b7b3132385952d976484..f6aacee3393de285b43740b25b124970b826f9d1 100644
--- a/core/src/main/java/hudson/tasks/Maven.java
+++ b/core/src/main/java/hudson/tasks/Maven.java
@@ -177,9 +177,6 @@ public class Maven extends Builder {
         AbstractProject proj = build.getProject();
 
         VariableResolver<String> vr = build.getBuildVariableResolver();
-        ParametersAction parameters = build.getAction(ParametersAction.class);
-        if(parameters!=null)
-            vr = parameters.createVariableResolver(build);
 
         String targets = Util.replaceMacro(this.targets,vr);