diff --git a/gmaven-plugin/src/main/java/org/codehaus/gmaven/plugin/MojoSupport.java b/gmaven-plugin/src/main/java/org/codehaus/gmaven/plugin/MojoSupport.java
index 4276a44e..a9c4f811 100644
--- a/gmaven-plugin/src/main/java/org/codehaus/gmaven/plugin/MojoSupport.java
+++ b/gmaven-plugin/src/main/java/org/codehaus/gmaven/plugin/MojoSupport.java
@@ -63,12 +63,16 @@ public abstract class MojoSupport
      */
     protected MavenProject project;
 
+    private static final Object lock = new Object();
+
     /**
      * Main Mojo execution hook.  Sub-class should use {@link #doExecute} instead.
      */
-    public synchronized void execute() throws MojoExecutionException, MojoFailureException {
+    public void execute() throws MojoExecutionException, MojoFailureException {
         try {
-            doExecute();
+            synchronized(lock) {
+                doExecute();
+            }
         }
         catch (Exception e) {
             //
diff --git a/pom.xml b/pom.xml
index b08a071f..70d89eb6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -645,7 +645,7 @@
                         <configuration>
                             <rules>
                                 <requireJavaVersion>
-                                    <version>[1.4, 1.8)</version>
+                                    <version>[1.4,)</version>
                                 </requireJavaVersion>
                                 <requireMavenVersion>
                                     <version>[2.0.10,)</version>