diff --git a/protected/java/test/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariantsIntegrationTest.java b/protected/java/test/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariantsIntegrationTest.java
index 25f6f3d97..c17c9ca55 100644
--- a/protected/java/test/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariantsIntegrationTest.java
+++ b/protected/java/test/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariantsIntegrationTest.java
@@ -47,6 +47,7 @@
 package org.broadinstitute.sting.gatk.walkers.variantutils;
 
 import org.broadinstitute.sting.WalkerTest;
+import org.broadinstitute.sting.utils.exceptions.UserException;
 import org.testng.annotations.Test;
 
 import java.util.Arrays;
@@ -91,4 +92,13 @@ public class LiftoverVariantsIntegrationTest extends WalkerTest {
                 Arrays.asList("0909a953291a5e701194668c9b8833ab"));
         executeTest("test liftover filtering of indels", spec);
     }
+
+    @Test
+    public void testLiftoverFailsWithNoOutput() {
+        WalkerTestSpec spec = new WalkerTestSpec(
+                "-T LiftoverVariants -R " + hg18Reference + " --variant:vcf " + privateTestDir + "liftover_test.vcf -chain " + validationDataLocation + "hg18ToHg19.broad.over.chain -dict /seq/references/Homo_sapiens_assembly19/v0/Homo_sapiens_assembly19.dict",
+                0,
+                UserException.class);
+        executeTest("test liftover fails with no output", spec);
+    }
 }
diff --git a/public/java/src/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariants.java b/public/java/src/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariants.java
index 17d50f101..0e38869c6 100644
--- a/public/java/src/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariants.java
+++ b/public/java/src/org/broadinstitute/sting/gatk/walkers/variantutils/LiftoverVariants.java
@@ -54,7 +54,11 @@ import java.io.File;
 import java.util.*;
 
 /**
- * Lifts a VCF file over from one build to another.  Note that the resulting VCF could be mis-sorted.
+ * Lifts a VCF file over from one build to another.
+ *
+ * Important note: the resulting VCF is not guaranteed to be valid according to the official specification.  The file could
+ * possibly be mis-sorted and the header may not be complete.  LiftoverVariants is intended to be the first of two processing steps
+ * for the liftover; the second step, FilterLiftedVariants, will produce a valid well-behaved VCF file.
  */
 @DocumentedGATKFeature( groupName = HelpConstants.DOCS_CAT_VARMANIP, extraDocs = {CommandLineGATK.class} )
 public class LiftoverVariants extends RodWalker<Integer, Integer> {
@@ -62,7 +66,7 @@ public class LiftoverVariants extends RodWalker<Integer, Integer> {
     @ArgumentCollection
     protected StandardVariantContextInputArgumentCollection variantCollection = new StandardVariantContextInputArgumentCollection();
 
-    @Output(doc="File to which variants should be written")
+    @Output(doc="File to which variants should be written", required=true, defaultToStdout=false)
     protected File file = null;
     protected VariantContextWriter writer = null;