diff --git a/java/src/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbes.java b/java/src/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbes.java
index 78f9c0540..0254c3bac 100755
--- a/java/src/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbes.java
+++ b/java/src/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbes.java
@@ -29,6 +29,7 @@ import net.sf.samtools.util.CloseableIterator;
 import org.broad.tribble.dbsnp.DbSNPCodec;
 import org.broadinstitute.sting.gatk.contexts.AlignmentContext;
 import org.broadinstitute.sting.gatk.contexts.ReferenceContext;
+import org.broadinstitute.sting.gatk.contexts.variantcontext.Allele;
 import org.broadinstitute.sting.gatk.contexts.variantcontext.VariantContext;
 import org.broadinstitute.sting.gatk.refdata.*;
 import org.broadinstitute.sting.gatk.refdata.tracks.builders.TribbleRMDTrackBuilder;
@@ -63,6 +64,8 @@ public class PickSequenomProbes extends RodWalker<String, String> {
     boolean omitWindow = false;
     @Argument(required = false, fullName="usePlinkRODNamingConvention", shortName="nameConvention",doc="Use the naming convention defined in PLINKROD")
     boolean useNamingConvention = false;
+    @Argument(required = false, fullName="noMaskWindow",shortName="nmw",doc="Do not mask bases within X bases of an event when designing probes")
+    int noMaskWindow = 0;
 
     private byte [] maskFlags = new byte[401];
 
@@ -139,7 +142,7 @@ public class PickSequenomProbes extends RodWalker<String, String> {
 
 		byte[] context_bases = ref.getBases();
 		for (int i = 0; i < 401; i++) {
-			if ( maskFlags[i] == 1 ) {
+		    if ( maskFlags[i] == 1 && ( i <  200 - noMaskWindow || i > 200 + getNoMaskWindowRightEnd(vc,noMaskWindow) ) ) {
                 context_bases[i] = 'N';
             }
             true_offset += 1;
@@ -188,5 +191,26 @@ public class PickSequenomProbes extends RodWalker<String, String> {
 		return "";
 	}
 
+    private int getNoMaskWindowRightEnd(VariantContext vc, int window) {
+        if ( window == 0 ) {
+            return 0;
+        }
+
+	if ( vc.isInsertion() ) {
+	    return window-1;
+	}
+
+        int max = 0;
+        for (Allele a : vc.getAlleles() ) {
+            if ( vc.isInsertion() ) {
+                logger.debug("Getting length of allele "+a.toString()+" it is "+a.getBases().length+" (ref allele is "+vc.getReference().toString()+")");
+            }
+            if ( a.getBases().length > max ) {
+                max = a.getBases().length;
+            }
+        }
+        return max+window-1;
+    }
+
     public void onTraversalDone(String sum) {}
 }
diff --git a/java/test/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbesIntegrationTest.java b/java/test/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbesIntegrationTest.java
index 348f27880..9a3ff8d3d 100755
--- a/java/test/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbesIntegrationTest.java
+++ b/java/test/org/broadinstitute/sting/gatk/walkers/sequenom/PickSequenomProbesIntegrationTest.java
@@ -23,7 +23,21 @@ public class PickSequenomProbesIntegrationTest extends WalkerTest {
                 + "-project_id 1kgp3_s4_lf -T PickSequenomProbes -L " + validationDataLocation +
                 "pickSeqIntegrationTest.interval_list -B input,VCF4,"+testVCF+" -o %s";
         WalkerTestSpec spec = new WalkerTestSpec(testArgs, 1,
-                Arrays.asList("cb1f57e8bcaec4b599be075b6d5288a1"));
+                Arrays.asList("8b5b715b9918a0b70f4868614f197b72"));
+        executeTest("Test probes", spec);
+    }
+
+    // 03c8cef968ae2d0ef5f51ac82b24f891
+
+    @Test
+    public void testProbesUsingDbSNPMaskWithNMW1() {
+    String testVCF = validationDataLocation + "pickSeqIntegrationTest.vcf";
+        String testArgs = "-snp_mask " + GATKDataLocation + "/dbsnp_130_b36.rod -R "
+                + oneKGLocation + "reference/human_b36_both.fasta -omitWindow -nameConvention "
+                + "-nmw 1 -project_id 1kgp3_s4_lf -T PickSequenomProbes -L " + validationDataLocation +
+	    "pickSeqIntegrationTest.interval_list -B input,VCF4,"+testVCF+" -o %s";
+        WalkerTestSpec spec = new WalkerTestSpec(testArgs, 1,
+						 Arrays.asList("03c8cef968ae2d0ef5f51ac82b24f891"));
         executeTest("Test probes", spec);
     }
 }