diff --git a/.travis.yml b/.travis.yml
index 6a319dd6..d028aa13 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,8 +16,10 @@ env:
 before_script:
   - git clone git://github.com/zenovich/runkit.git && cd runkit && phpize && ./configure && make && make install && cd ..
   - echo "extension=runkit.so" >> `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"`
+  - sh -c "if [ '$TRAVIS_PHP_VERSION' = '5.5' ]; then composer install --dev --no-interaction; fi"
 
 script:
+  - sh -c "if [ '$TRAVIS_PHP_VERSION' = '5.5' ]; then vendor/bin/phpcs -s --extensions=php --standard=tests/code_sniffer_ruleset.xml phpseclib/; fi"
   - phpunit --verbose --coverage-text --coverage-html code_coverage/
 
 after_success:
diff --git a/composer.json b/composer.json
index a660afa5..e2eddf2e 100644
--- a/composer.json
+++ b/composer.json
@@ -33,6 +33,9 @@
     "require": {
         "php": ">=5.0.0"
     },
+    "require-dev": {
+        "squizlabs/php_codesniffer": "1.*"
+    },
     "suggest": {
         "ext-mcrypt": "Install the Mcrypt extension in order to speed up a wide variety of cryptographic operations.",
         "ext-gmp": "Install the GMP (GNU Multiple Precision) extension in order to speed up arbitrary precision integer arithmetic operations.",
diff --git a/composer.lock b/composer.lock
new file mode 100644
index 00000000..2bdf3602
--- /dev/null
+++ b/composer.lock
@@ -0,0 +1,96 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file"
+    ],
+    "hash": "e692359d277b10176319a11c2aef51aa",
+    "packages": [
+
+    ],
+    "packages-dev": [
+        {
+            "name": "squizlabs/php_codesniffer",
+            "version": "1.4.7",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/squizlabs/PHP_CodeSniffer.git",
+                "reference": "df764a1604607ea61c4eeea5410666e27cb37a8b"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/squizlabs/PHP_CodeSniffer/zipball/df764a1604607ea61c4eeea5410666e27cb37a8b",
+                "reference": "df764a1604607ea61c4eeea5410666e27cb37a8b",
+                "shasum": ""
+            },
+            "require": {
+                "ext-tokenizer": "*",
+                "php": ">=5.1.2"
+            },
+            "suggest": {
+                "phpunit/php-timer": "dev-master"
+            },
+            "bin": [
+                "scripts/phpcs"
+            ],
+            "type": "library",
+            "autoload": {
+                "classmap": [
+                    "CodeSniffer.php",
+                    "CodeSniffer/CLI.php",
+                    "CodeSniffer/Exception.php",
+                    "CodeSniffer/File.php",
+                    "CodeSniffer/MultiFileSniff.php",
+                    "CodeSniffer/Report.php",
+                    "CodeSniffer/Reporting.php",
+                    "CodeSniffer/Sniff.php",
+                    "CodeSniffer/Tokens.php",
+                    "CodeSniffer/Reports/",
+                    "CodeSniffer/CommentParser/",
+                    "CodeSniffer/Tokenizers/",
+                    "CodeSniffer/DocGenerators/",
+                    "CodeSniffer/Standards/AbstractPatternSniff.php",
+                    "CodeSniffer/Standards/AbstractScopeSniff.php",
+                    "CodeSniffer/Standards/AbstractVariableSniff.php",
+                    "CodeSniffer/Standards/IncorrectPatternException.php",
+                    "CodeSniffer/Standards/Generic/Sniffs/",
+                    "CodeSniffer/Standards/MySource/Sniffs/",
+                    "CodeSniffer/Standards/PEAR/Sniffs/",
+                    "CodeSniffer/Standards/PSR1/Sniffs/",
+                    "CodeSniffer/Standards/PSR2/Sniffs/",
+                    "CodeSniffer/Standards/Squiz/Sniffs/",
+                    "CodeSniffer/Standards/Zend/Sniffs/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Greg Sherwood",
+                    "role": "lead"
+                }
+            ],
+            "description": "PHP_CodeSniffer tokenises PHP, JavaScript and CSS files and detects violations of a defined set of coding standards.",
+            "homepage": "http://www.squizlabs.com/php-codesniffer",
+            "keywords": [
+                "phpcs",
+                "standards"
+            ],
+            "time": "2013-09-26 00:08:21"
+        }
+    ],
+    "aliases": [
+
+    ],
+    "minimum-stability": "stable",
+    "stability-flags": [
+
+    ],
+    "platform": {
+        "php": ">=5.0.0"
+    },
+    "platform-dev": [
+
+    ]
+}
diff --git a/tests/code_sniffer_ruleset.xml b/tests/code_sniffer_ruleset.xml
new file mode 100644
index 00000000..e321c7d4
--- /dev/null
+++ b/tests/code_sniffer_ruleset.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0"?>
+<ruleset name="phpseclib Standard">
+
+ <description>phpseclib coding standard</description>
+
+ <!-- "for (; bar; )" should be "while (bar)" instead -->
+ <rule ref="Generic.CodeAnalysis.ForLoopShouldBeWhileLoop" />
+
+ <!-- A method MUST not only call its parent -->
+ <rule ref="Generic.CodeAnalysis.UselessOverridingMethod" />
+
+ <!-- All code files MUST use only UTF-8 without BOM. -->
+ <rule ref="Generic.Files.ByteOrderMark" />
+
+ <!-- All code files MUST use the Unix LF (linefeed) line ending. -->
+ <rule ref="Generic.Files.LineEndings" />
+
+ <!-- Class constants MUST be declared in all upper case with underscore separators. -->
+ <rule ref="Generic.NamingConventions.UpperCaseConstantName" />
+
+ <!-- Only <?php, no short tags. -->
+ <rule ref="Generic.PHP.DisallowShortOpenTag.EchoFound" />
+
+ <!-- PHP keywords MUST be in lower case. -->
+ <rule ref="Generic.PHP.LowerCaseKeyword" />
+
+ <!-- Spaces MUST be used for indentation -->
+ <rule ref="Generic.WhiteSpace.DisallowTabIndent" />
+
+ <!-- Method arguments with default values MUST go at the end of the argument list. -->
+ <rule ref="PEAR.Functions.ValidDefaultValue" />
+
+ <!-- In the argument list, there MUST NOT be a space before each comma,
+      and there MUST be one space after each comma. -->
+ <rule ref="Squiz.Functions.FunctionDeclarationArgumentSpacing">
+  <properties>
+   <property name="equalsSpacing" value="1"/>
+  </properties>
+ </rule>
+ <rule ref="Squiz.Functions.FunctionDeclarationArgumentSpacing.SpacingAfterHint" />
+
+ <!-- The ?> closing tag MUST be omitted from files containing only PHP. -->
+ <rule ref="Zend.Files.ClosingTag" />
+
+</ruleset>