diff --git a/core/src/main/java/hudson/tasks/Maven.java b/core/src/main/java/hudson/tasks/Maven.java
index b54fbddd0a8ad1a7646b02a59a851af9479991b5..998ab187f663a1960f89486c32dcebcd32fa2df7 100644
--- a/core/src/main/java/hudson/tasks/Maven.java
+++ b/core/src/main/java/hudson/tasks/Maven.java
@@ -221,6 +221,10 @@ public class Maven extends Builder {
             new FormFieldValidator(req,rsp,true) {
                 public void check() throws IOException, ServletException {
                     File f = getFileParameter("value");
+                    if(f.getPath().equals("")) {
+                        error("MAVEN_HOME is required");
+                        return;
+                    }
                     if(!f.isDirectory()) {
                         error(f+" is not a directory");
                         return;