diff --git a/README.md b/README.md
index 811b930..886df1a 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,9 @@ Set the maximum allowed length of the password
 ##### setCheckContainsLetters(boolean $value)
 Set the flag to check that the password contains at least one letter
 
+##### setCheckContainsCapitals(boolean $value)
+Set the flag to check that the password contains at least one *capital* letter
+
 ##### setCheckContainsNumbers(boolean $value)
 Set the flag to check that the password contains at least one number
 
diff --git a/src/Verifier.php b/src/Verifier.php
index 0791a35..49b8aa0 100644
--- a/src/Verifier.php
+++ b/src/Verifier.php
@@ -42,6 +42,10 @@ public function checkPassword($password) {
       $this->errors['letters'] = "Password must contain at least one letter";
     }
 
+    if ($this->checkCapitals && !preg_match('/[A-Z]/', $password)) {
+      $this->errors['capitals'] = "Password must contain at least one capital letter";
+    }
+
     if ($this->checkNumbers && !preg_match('/[0-9]/', $password)) {
       $this->errors['numbers'] = "Password must contain at least one number";
     }
@@ -88,7 +92,7 @@ public function setMaxLength($length) {
     return $this;
   }
 
-  public function setCheckContainsLetters($value) {
+  public function setCheckContainsLetters($value = true) {
     if ($value !== false && $value !== true) {
       throw new SetConstraintException("setCheckContainsLetters value must be of type boolean", 4);
     }
@@ -98,7 +102,17 @@ public function setCheckContainsLetters($value) {
     return $this;
   }
 
-  public function setCheckContainsNumbers($value) {
+  public function setCheckContainsCapitals($value = true) {
+    if ($value !== false && $value !== true) {
+      throw new SetConstraintException("setCheckContainsCapitals value must be of type boolean", 8);
+    }
+    else {
+      $this->checkCapitals = $value;
+    }
+    return $this;
+  }
+
+  public function setCheckContainsNumbers($value = true) {
     if ($value !== false && $value !== true) {
       throw new SetConstraintException("setCheckContainsNumbers value must be of type boolean", 5);
     }
@@ -108,7 +122,7 @@ public function setCheckContainsNumbers($value) {
     return $this;
   }
 
-  public function setCheckContainsSpecialChrs($value) {
+  public function setCheckContainsSpecialChrs($value = true) {
     if ($value !== false && $value !== true) {
       throw new SetConstraintException("setCheckContainsSpecialChrs value must be of type boolean", 6);
     }
@@ -118,7 +132,7 @@ public function setCheckContainsSpecialChrs($value) {
     return $this;
   }
 
-  public function setCheckBlacklist($value) {
+  public function setCheckBlacklist($value = true) {
     if ($value !== false && $value !== true) {
       throw new SetConstraintException("setCheckBlacklist value must be of type boolean", 7);
     }
diff --git a/tests/ExceptionTest.php b/tests/ExceptionTest.php
index 3c073e3..725474d 100644
--- a/tests/ExceptionTest.php
+++ b/tests/ExceptionTest.php
@@ -51,6 +51,16 @@ public function testCheckContainsLettersInputIsBoolean() {
     $passwordVerifier->setCheckContainsLetters('hello');
   }
 
+  /**
+  * @expectedException acurrieclark\PhpPasswordVerifier\Exception\SetConstraintException
+  * @expectedExceptionCode 8
+  */
+
+  public function testCheckContainsCapitalsInputIsBoolean() {
+    $passwordVerifier = new Verifier();
+    $passwordVerifier->setCheckContainsCapitals('hello');
+  }
+
   /**
   * @expectedException acurrieclark\PhpPasswordVerifier\Exception\SetConstraintException
   * @expectedExceptionCode 5
diff --git a/tests/VerifyTest.php b/tests/VerifyTest.php
index c2f8893..a0e177f 100644
--- a/tests/VerifyTest.php
+++ b/tests/VerifyTest.php
@@ -66,6 +66,20 @@ public function testContainsLetterPass() {
     $this->assertEquals(empty($passwordVerifier->getErrors()), true);
   }
 
+  public function testContainsCapitalsFail() {
+    $passwordVerifier = new Verifier();
+    $passwordVerifier->setCheckContainsCapitals(true);
+    $this->assertEquals($passwordVerifier->checkPassword('asdf'), false);
+    $this->assertEquals(isset($passwordVerifier->getErrors()['capitals']), true);
+  }
+
+  public function testContainsCapitalsPass() {
+    $passwordVerifier = new Verifier();
+    $passwordVerifier->setCheckContainsCapitals(true);
+    $this->assertEquals($passwordVerifier->checkPassword('Asdf'), true);
+    $this->assertEquals(empty($passwordVerifier->getErrors()), true);
+  }
+
   public function testContainsNumberFail() {
     $passwordVerifier = new Verifier();
     $passwordVerifier->setCheckContainsNumbers(true);