diff --git a/src/Numerics/Integration/Algorithms/DoubleExponentialTransformation.cs b/src/Numerics/Integration/Algorithms/DoubleExponentialTransformation.cs
index e9458a0c..06a3d187 100644
--- a/src/Numerics/Integration/Algorithms/DoubleExponentialTransformation.cs
+++ b/src/Numerics/Integration/Algorithms/DoubleExponentialTransformation.cs
@@ -535,7 +535,7 @@ namespace MathNet.Numerics.Integration.Algorithms
         /// Abscissa vector per level provider.
         /// </summary>
         /// <returns>Level Enumerator.</returns>
-        private static IEnumerable<double[]> ProvideLevelAbcissas()
+        internal static IEnumerable<double[]> ProvideLevelAbcissas()
         {
             for (int i = 0; i < NumberOfMaximumLevels; i++)
             {
@@ -547,7 +547,7 @@ namespace MathNet.Numerics.Integration.Algorithms
         /// Weight vector per level provider.
         /// </summary>
         /// <returns>Level Enumerator.</returns>
-        private static IEnumerable<double[]> ProvideLevelWeights()
+        internal static IEnumerable<double[]> ProvideLevelWeights()
         {
             for (int i = 0; i < NumberOfMaximumLevels; i++)
             {
diff --git a/src/Numerics/Integration/Algorithms/NewtonCotesTrapeziumRule.cs b/src/Numerics/Integration/Algorithms/NewtonCotesTrapeziumRule.cs
index a3b5cc91..5b2d6902 100644
--- a/src/Numerics/Integration/Algorithms/NewtonCotesTrapeziumRule.cs
+++ b/src/Numerics/Integration/Algorithms/NewtonCotesTrapeziumRule.cs
@@ -52,6 +52,11 @@ namespace MathNet.Numerics.Integration.Algorithms
             double intervalBegin,
             double intervalEnd)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
             return (intervalEnd - intervalBegin) / 2 * (f(intervalBegin) + f(intervalEnd));
         }
 
@@ -69,6 +74,11 @@ namespace MathNet.Numerics.Integration.Algorithms
             double intervalEnd,
             int numberOfPartitions)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
             if (numberOfPartitions <= 0)
             {
                 throw new ArgumentOutOfRangeException("numberOfPartitions", Resources.ArgumentPositive);
@@ -102,6 +112,11 @@ namespace MathNet.Numerics.Integration.Algorithms
             double intervalEnd,
             double targetError)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
             int numberOfPartitions = 1;
             double step = intervalEnd - intervalBegin;
             double sum = 0.5 * step * (f(intervalBegin) + f(intervalEnd));
@@ -147,6 +162,21 @@ namespace MathNet.Numerics.Integration.Algorithms
             double levelOneStep,
             double targetRelativeError)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
+            if (levelAbscissas == null)
+            {
+                throw new ArgumentNullException("levelAbscissas");
+            }
+
+            if (levelWeights == null)
+            {
+                throw new ArgumentNullException("levelWeights");
+            }
+
             double linearSlope = 0.5 * (intervalEnd - intervalBegin);
             double linearOffset = 0.5 * (intervalEnd + intervalBegin);
             targetRelativeError /= 5 * linearSlope;
diff --git a/src/Numerics/Integration/Algorithms/SimpsonRule.cs b/src/Numerics/Integration/Algorithms/SimpsonRule.cs
index 1d2def00..bc563d14 100644
--- a/src/Numerics/Integration/Algorithms/SimpsonRule.cs
+++ b/src/Numerics/Integration/Algorithms/SimpsonRule.cs
@@ -49,6 +49,11 @@ namespace MathNet.Numerics.Integration.Algorithms
             double intervalBegin,
             double intervalEnd)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
             double midpoint = (intervalEnd + intervalBegin) / 2;
             return (intervalEnd - intervalBegin) / 6 * (f(intervalBegin) + f(intervalEnd) + (4 * f(midpoint)));
         }
@@ -67,6 +72,11 @@ namespace MathNet.Numerics.Integration.Algorithms
             double intervalEnd,
             int numberOfPartitions)
         {
+            if (f == null)
+            {
+                throw new ArgumentNullException("f");
+            }
+
             if (numberOfPartitions <= 0)
             {
                 throw new ArgumentOutOfRangeException("numberOfPartitions", Resources.ArgumentPositive);
@@ -85,7 +95,7 @@ namespace MathNet.Numerics.Integration.Algorithms
             double sum = f(intervalBegin) + f(intervalEnd);
             for (int i = 0; i < numberOfPartitions - 1; i++)
             {
-                // NOTE (ruegg, 2009-01-07): Do not combine intervalBegin and offset (numerical stability)
+                // NOTE (cdrnet, 2009-01-07): Do not combine intervalBegin and offset (numerical stability)
                 sum += m * f(intervalBegin + offset);
                 m = 6 - m;
                 offset += step;
@@ -94,4 +104,4 @@ namespace MathNet.Numerics.Integration.Algorithms
             return factor * sum;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/UnitTests/IntegrationTests/IntegrationTest.cs b/src/UnitTests/IntegrationTests/IntegrationTest.cs
index e2dee5d8..0038941a 100644
--- a/src/UnitTests/IntegrationTests/IntegrationTest.cs
+++ b/src/UnitTests/IntegrationTests/IntegrationTest.cs
@@ -26,13 +26,14 @@
 // OTHER DEALINGS IN THE SOFTWARE.
 // </copyright>
 
-
 namespace MathNet.Numerics.UnitTests.IntegrationTests
 {
     using System;
+    using System.Linq.Expressions;
     using Integration;
     using Integration.Algorithms;
     using MbUnit.Framework;
+    using MbUnit.Framework.ContractVerifiers;
 
     [TestFixture]
     public class IntegrationTest
@@ -65,6 +66,18 @@ namespace MathNet.Numerics.UnitTests.IntegrationTests
                 "Basic Target 1e-10");
         }
 
+        [VerifyContract]
+        public readonly IContract FacadeIntegrateChecksArguments =
+            new ArgumentCheckContract<double>
+            {
+                TypicalUses =
+                    new Expression<Func<double>>[]
+                    {
+                        () => Integrate.OnClosedInterval(x => 2 * x, StartA, StopA),
+                        () => Integrate.OnClosedInterval(x => 2 * x, StartA, StopA, 1e-5)
+                    }
+            };
+
         [Test]
         [Row(1e-5)]
         [Row(1e-13)]
@@ -79,6 +92,13 @@ namespace MathNet.Numerics.UnitTests.IntegrationTests
                 "DET Adaptive {0}", targetRelativeError);
         }
 
+        [VerifyContract]
+        public readonly IContract DoubleExponentialTransformationIntegrateChecksArguments =
+            new ArgumentCheckContract<double>
+            {
+                TypicalUse = () => (new DoubleExponentialTransformation()).Integrate(x => 2 * x, StartA, StopA, 1e-5)
+            };
+
         [Test]
         public void TrapeziumRuleSupportsTwoPointIntegration()
         {
@@ -117,6 +137,28 @@ namespace MathNet.Numerics.UnitTests.IntegrationTests
                 "Adaptive {0}", targetRelativeError);
         }
 
+        [VerifyContract]
+        public readonly IContract TrapeziumRuleIntegrateChecksArguments =
+            new ArgumentCheckContract<double>
+            {
+                TypicalUses =
+                    new Expression<Func<double>>[]
+                    {
+                        () => NewtonCotesTrapeziumRule.IntegrateTwoPoint(x => 2 * x, StartA, StopA),
+                        () => NewtonCotesTrapeziumRule.IntegrateComposite(x => 2 * x, StartA, StopA, 2),
+                        () => NewtonCotesTrapeziumRule.IntegrateAdaptive(x => 2 * x, StartA, StopA, 1e-5),
+                        () => NewtonCotesTrapeziumRule.IntegrateAdaptiveTransformedOdd(
+                                  x => 2 * x,
+                                  StartA,
+                                  StopA,
+                                  DoubleExponentialTransformation.ProvideLevelAbcissas(),
+                                  DoubleExponentialTransformation.ProvideLevelWeights(),
+                                  1,
+                                  1e-5)
+                    },
+                BadUse = () => NewtonCotesTrapeziumRule.IntegrateComposite(x => 2 * x, StartA, StopA, 0)
+            };
+
         [Test]
         public void SimpsonRuleSupportsThreePointIntegration()
         {
@@ -141,5 +183,23 @@ namespace MathNet.Numerics.UnitTests.IntegrationTests
                 maxRelativeError * TargetAreaA,
                 "Composite {0} Partitions", partitions);
         }
+
+        [VerifyContract]
+        public readonly IContract SimpsonRuleIntegrateChecksArguments =
+            new ArgumentCheckContract<double>
+            {
+                TypicalUses =
+                    new Expression<Func<double>>[]
+                    {
+                        () => SimpsonRule.IntegrateThreePoint(x => 2 * x, StartA, StopA),
+                        () => SimpsonRule.IntegrateComposite(x => 2 * x, StartA, StopA, 2)
+                    },
+                BadUses =
+                    new Func<double>[]
+                    {
+                        () => SimpsonRule.IntegrateComposite(x => 2 * x, StartA, StopA, 0),
+                        () => SimpsonRule.IntegrateComposite(x => 2 * x, StartA, StopA, 3)
+                    }
+            };
     }
 }