diff --git a/src/main/java/com/clivern/kangaroo/constraint/IntegerConstraint.java b/src/main/java/com/clivern/kangaroo/constraint/IntegerConstraint.java
index bf591e6..bd8f3d2 100644
--- a/src/main/java/com/clivern/kangaroo/constraint/IntegerConstraint.java
+++ b/src/main/java/com/clivern/kangaroo/constraint/IntegerConstraint.java
@@ -57,7 +57,14 @@ public Boolean isValidType() {
 
     /** {@inheritDoc} */
     public Boolean validate() {
-        return false;
+        Boolean status = true;
+
+        if (!this.isValidType()) {
+            status &= false;
+            this.errors.add(String.format("Error! Field %s must be an integer.", this.fieldName));
+        }
+
+        return status;
     }
 
     /** {@inheritDoc} */
diff --git a/src/test/java/com/clivern/kangaroo/constraint/IntegerConstraintTest.java b/src/test/java/com/clivern/kangaroo/constraint/IntegerConstraintTest.java
index 010f994..8f05913 100644
--- a/src/test/java/com/clivern/kangaroo/constraint/IntegerConstraintTest.java
+++ b/src/test/java/com/clivern/kangaroo/constraint/IntegerConstraintTest.java
@@ -24,26 +24,64 @@ public class IntegerConstraintTest {
 
     @Test
     public void testStringValidation() {
-        IntegerConstraint intConstraint = new IntegerConstraint();
+        IntegerConstraint integerConstraint1 = new IntegerConstraint();
+        integerConstraint1.setFieldName("fieldName");
+        assertEquals(integerConstraint1.getFieldName(), "fieldName");
+        integerConstraint1.setValue(1);
+        assertEquals(integerConstraint1.getValue(), new Integer("1"));
+        assertEquals(integerConstraint1.validate(), true);
+        assertEquals(integerConstraint1.hasErrors(), false);
+        assertEquals(integerConstraint1.getErrors(), new ArrayList<String>());
 
-        intConstraint.setValue(1);
-        assertEquals(intConstraint.getValue(), new Integer("1"));
-        assertEquals(intConstraint.isValidType(), true);
+        IntegerConstraint integerConstraint2 = new IntegerConstraint();
+        integerConstraint2.setFieldName("fieldName");
+        assertEquals(integerConstraint2.getFieldName(), "fieldName");
+        integerConstraint2.setValue(-1);
+        assertEquals(integerConstraint2.getValue(), new Integer("-1"));
+        assertEquals(integerConstraint2.validate(), true);
+        assertEquals(integerConstraint2.hasErrors(), false);
+        assertEquals(integerConstraint2.getErrors(), new ArrayList<String>());
 
-        intConstraint.setValue("");
-        assertEquals(intConstraint.getValue(), new Integer("0"));
-        assertEquals(intConstraint.isValidType(), false);
-
-        intConstraint.setValue(null);
-        assertEquals(intConstraint.getValue(), new Integer("0"));
-        assertEquals(intConstraint.isValidType(), false);
+        IntegerConstraint integerConstraint3 = new IntegerConstraint();
+        integerConstraint3.setFieldName("fieldName");
+        assertEquals(integerConstraint3.getFieldName(), "fieldName");
+        integerConstraint3.setValue(1.2);
+        assertEquals(integerConstraint3.getValue(), new Integer("0"));
+        assertEquals(integerConstraint3.validate(), false);
+        assertEquals(integerConstraint3.hasErrors(), true);
+        ArrayList<String> errors = new ArrayList<String>();
+        errors.add(
+                String.format(
+                        "Error! Field %s must be an integer.", integerConstraint3.getFieldName()));
+        assertEquals(integerConstraint3.getErrors(), errors);
 
         ArrayList<String> list = new ArrayList<String>();
         list.add("A");
-        list.add("B");
-        list.add("C");
-        intConstraint.setValue(list);
-        assertEquals(intConstraint.getValue(), new Integer("0"));
-        assertEquals(intConstraint.isValidType(), false);
+        IntegerConstraint integerConstraint4 = new IntegerConstraint();
+        integerConstraint4.setFieldName("fieldName");
+        assertEquals(integerConstraint4.getFieldName(), "fieldName");
+        integerConstraint4.setValue(list);
+        assertEquals(integerConstraint4.getValue(), new Integer("0"));
+        assertEquals(integerConstraint4.validate(), false);
+        assertEquals(integerConstraint4.hasErrors(), true);
+        assertEquals(integerConstraint4.getErrors(), errors);
+
+        IntegerConstraint integerConstraint5 = new IntegerConstraint();
+        integerConstraint5.setFieldName("fieldName");
+        assertEquals(integerConstraint5.getFieldName(), "fieldName");
+        integerConstraint5.setValue(0);
+        assertEquals(integerConstraint5.getValue(), new Integer("0"));
+        assertEquals(integerConstraint5.validate(), true);
+        assertEquals(integerConstraint5.hasErrors(), false);
+        assertEquals(integerConstraint5.getErrors(), new ArrayList<String>());
+
+        IntegerConstraint integerConstraint6 = new IntegerConstraint();
+        integerConstraint6.setFieldName("fieldName");
+        assertEquals(integerConstraint6.getFieldName(), "fieldName");
+        integerConstraint6.setValue(100);
+        assertEquals(integerConstraint6.getValue(), new Integer("100"));
+        assertEquals(integerConstraint6.validate(), true);
+        assertEquals(integerConstraint6.hasErrors(), false);
+        assertEquals(integerConstraint6.getErrors(), new ArrayList<String>());
     }
 }