diff --git a/src/main/java/org/apache/commons/math3/special/Gamma.java b/src/main/java/org/apache/commons/math3/special/Gamma.java
index 65bee5af0..be669f1e0 100644
--- a/src/main/java/org/apache/commons/math3/special/Gamma.java
+++ b/src/main/java/org/apache/commons/math3/special/Gamma.java
@@ -706,7 +706,9 @@ public class Gamma {
      */
     public static double gamma(final double x) {
 
-        // TODO Check whether x is a negative integer
+        if ((x == FastMath.rint(x)) && (x <= 0.0)) {
+            return Double.NaN;
+        }
 
         final double ret;
         final double absX = FastMath.abs(x);
diff --git a/src/test/java/org/apache/commons/math3/special/GammaTest.java b/src/test/java/org/apache/commons/math3/special/GammaTest.java
index 205655d79..8c1a29289 100644
--- a/src/test/java/org/apache/commons/math3/special/GammaTest.java
+++ b/src/test/java/org/apache/commons/math3/special/GammaTest.java
@@ -954,6 +954,14 @@ public class GammaTest {
         }
     }
 
+    @Test
+    public void testGammaNegativeInteger() {
+
+        for (int i = -100; i <= 0; i++) {
+            Assert.assertTrue(Integer.toString(i), Double.isNaN(Gamma.gamma(i)));
+        }
+    }
+
     /**
      * Reference data for the {@link Gamma#logGammaSum(double, double)}
      * function. This data was generated with the following