diff --git a/public/java/src/org/broadinstitute/sting/utils/recalibration/RecalDatum.java b/public/java/src/org/broadinstitute/sting/utils/recalibration/RecalDatum.java
index 4eb069542..eebc86b6b 100755
--- a/public/java/src/org/broadinstitute/sting/utils/recalibration/RecalDatum.java
+++ b/public/java/src/org/broadinstitute/sting/utils/recalibration/RecalDatum.java
@@ -341,12 +341,22 @@ public class RecalDatum {
         return log10QempPriorCache[difference];
     }
 
-    static protected double log10QempLikelihood(final double Qempirical, final long nObservations, final long nErrors) {
+    static protected double log10QempLikelihood(final double Qempirical, long nObservations, long nErrors) {
         if ( nObservations == 0 )
             return 0.0;
 
+        // the binomial code requires ints as input (because it does caching).  This should theoretically be fine because
+        // there is plenty of precision in 2^31 observations, but we need to make sure that we don't have overflow
+        // before casting down to an int.
+        if ( nObservations > Integer.MAX_VALUE ) {
+            // we need to decrease nErrors by the same fraction that we are decreasing nObservations
+            final double fraction = (double)Integer.MAX_VALUE / (double)nObservations;
+            nErrors = Math.round((double)nErrors * fraction);
+            nObservations = Integer.MAX_VALUE;
+        }
+
         // this is just a straight binomial PDF
-        double log10Prob = MathUtils.log10BinomialProbability(longToInt(nObservations), longToInt(nErrors), QualityUtils.qualToErrorProbLog10((byte)(int)Qempirical));
+        double log10Prob = MathUtils.log10BinomialProbability((int)nObservations, (int)nErrors, QualityUtils.qualToErrorProbLog10((byte)(int)Qempirical));
         if ( Double.isInfinite(log10Prob) || Double.isNaN(log10Prob) )
             log10Prob = -Double.MAX_VALUE;
 
@@ -355,8 +365,4 @@ public class RecalDatum {
 
         return log10Prob;
     }
-
-    static protected int longToInt(final long l) {
-        return (l > Integer.MAX_VALUE) ? Integer.MAX_VALUE : (int)l;
-    }
 }
\ No newline at end of file
diff --git a/public/java/test/org/broadinstitute/sting/utils/recalibration/RecalDatumUnitTest.java b/public/java/test/org/broadinstitute/sting/utils/recalibration/RecalDatumUnitTest.java
index 2305fe566..9b2938d80 100644
--- a/public/java/test/org/broadinstitute/sting/utils/recalibration/RecalDatumUnitTest.java
+++ b/public/java/test/org/broadinstitute/sting/utils/recalibration/RecalDatumUnitTest.java
@@ -206,7 +206,7 @@ public class RecalDatumUnitTest extends BaseTest {
     }
 
     @Test
-    public void testlog10QempLikelihood() {
+    public void testBayesianEstimateOfEmpiricalQuality() {
 
         final int Qrep = 20;
 
@@ -229,7 +229,7 @@ public class RecalDatumUnitTest extends BaseTest {
     }
 
     @Test
-    public void testBayesianEstimateOfEmpiricalQuality() {
+    public void testlog10QempLikelihood() {
 
         final double[] Qemps = new double[] { 0.0, 10.0, 20.0, 30.0 };
         final int[] observations = new int[] {0, 10, 1000, 1000000};
@@ -248,16 +248,12 @@ public class RecalDatumUnitTest extends BaseTest {
                 }
             }
         }
-    }
 
-    @Test
-    public void testLongToInt() {
-        long l = new Long((long)Integer.MAX_VALUE);
-        int i = RecalDatum.longToInt(l);
-        Assert.assertEquals(i, Integer.MAX_VALUE);
-
-        l++;
-        i = RecalDatum.longToInt(l);
-        Assert.assertEquals(i, Integer.MAX_VALUE);
+        long bigNum = new Long((long)Integer.MAX_VALUE);
+        bigNum *= 2L;
+        final double log10likelihood = RecalDatum.log10QempLikelihood(30, bigNum, 100000);
+        Assert.assertTrue(log10likelihood < 0.0);
+        Assert.assertFalse(Double.isInfinite(log10likelihood));
+        Assert.assertFalse(Double.isNaN(log10likelihood));
     }
 }
\ No newline at end of file