diff --git a/maven-plugin/src/main/java/hudson/maven/MavenBuild.java b/maven-plugin/src/main/java/hudson/maven/MavenBuild.java
index 9d5720e35afa30a8ea063984d1286df2ed3ed2f3..0868df55c23b6171e4b42f56e171956ff99c3782 100644
--- a/maven-plugin/src/main/java/hudson/maven/MavenBuild.java
+++ b/maven-plugin/src/main/java/hudson/maven/MavenBuild.java
@@ -36,6 +36,7 @@ import hudson.model.Result;
 import hudson.model.Run;
 import hudson.model.Cause.UpstreamCause;
 import hudson.model.Environment;
+import hudson.model.TaskListener;
 import hudson.remoting.Channel;
 import hudson.scm.ChangeLogSet;
 import hudson.scm.ChangeLogSet.Entry;
@@ -170,6 +171,19 @@ public class MavenBuild extends AbstractBuild<MavenModule,MavenBuild> {
         return true;
     }
 
+    /**
+     * Exposes {@code MAVEN_OPTS} to forked processes.
+     *
+     * <p>
+     * See {@link MavenModuleSetBuild#getEnvironment(TaskListener)}  for discussion.
+     */
+    @Override
+    public EnvVars getEnvironment(TaskListener log) throws IOException, InterruptedException {
+        EnvVars envs = super.getEnvironment(log);
+        envs.put("MAVEN_OPTS",project.getParent().getMavenOpts());
+        return envs;
+    }
+
     public void registerAsProjectAction(MavenReporter reporter) {
         if(projectActionReporters==null)
             projectActionReporters = new ArrayList<MavenReporter>();
diff --git a/maven-plugin/src/main/java/hudson/maven/MavenModuleSetBuild.java b/maven-plugin/src/main/java/hudson/maven/MavenModuleSetBuild.java
index 9681c1a9a46bac578fc14694ef676bbd23d93177..f4e1609e145852100b6bd6a5fccbbe951a220ee2 100644
--- a/maven-plugin/src/main/java/hudson/maven/MavenModuleSetBuild.java
+++ b/maven-plugin/src/main/java/hudson/maven/MavenModuleSetBuild.java
@@ -42,6 +42,7 @@ import hudson.model.Hudson;
 import hudson.model.ParametersAction;
 import hudson.model.Result;
 import hudson.model.Computer;
+import hudson.model.TaskListener;
 import hudson.model.Cause.UpstreamCause;
 import hudson.remoting.Channel;
 import hudson.remoting.VirtualChannel;
@@ -111,6 +112,21 @@ public final class MavenModuleSetBuild extends AbstractBuild<MavenModuleSet,Mave
         super(project, buildDir);
     }
 
+    /**
+     * Exposes {@code MAVEN_OPTS} to forked processes.
+     *
+     * When we fork Maven, we do so directly by executing Java, thus this environment variable
+     * is pointless (we have to tweak JVM launch option correctly instead, which can be seen in
+     * {@link MavenProcessFactory}), but setting the environment variable explicitly is still
+     * useful in case this Maven forks other Maven processes via normal way. See HUDSON-3644.
+     */
+    @Override
+    public EnvVars getEnvironment(TaskListener log) throws IOException, InterruptedException {
+        EnvVars envs = super.getEnvironment(log);
+        envs.put("MAVEN_OPTS",project.getMavenOpts());
+        return envs;
+    }
+
     /**
      * Displays the combined status of all modules.
      * <p>
diff --git a/maven-plugin/src/main/java/hudson/maven/MavenProcessFactory.java b/maven-plugin/src/main/java/hudson/maven/MavenProcessFactory.java
index a933d5f54de0c07c31401dca92a6ee00a7a11932..44e208a00a1987317a464f650c650406a90c7847 100644
--- a/maven-plugin/src/main/java/hudson/maven/MavenProcessFactory.java
+++ b/maven-plugin/src/main/java/hudson/maven/MavenProcessFactory.java
@@ -253,7 +253,7 @@ final class MavenProcessFactory implements ProcessCache.Factory {
         if(jdk==null) {
             args.add("java");
         } else {
-            args.add(jdk.getJavaHome()+"/bin/java"); // use JDK.getExecutable() here ?
+            args.add(jdk.getHome()+"/bin/java"); // use JDK.getExecutable() here ?
         }
 
         if(debugPort!=0)