diff --git a/PHPCI/Builder.php b/PHPCI/Builder.php
index 651e6489..d04f8bd9 100644
--- a/PHPCI/Builder.php
+++ b/PHPCI/Builder.php
@@ -86,8 +86,10 @@ class Builder
 		$this->store->save($this->build);
 	}
 
-	public function executeCommand($command)
+	public function executeCommand()
 	{
+		$command = call_user_func_array('sprintf', func_get_args());
+		
 		$this->log('Executing: ' . $command, '	');
 
 		$output	= '';
@@ -179,7 +181,7 @@ class Builder
 	protected function removeBuild()
 	{
 		$this->log('Removing build.');
-		shell_exec('rm -Rf ' . $this->buildPath);
+		shell_exec(sprintf('rm -Rf "%s"', $this->buildPath));
 	}
 
 	protected function executePlugins($stage)
diff --git a/PHPCI/Model/Build/LocalBuild.php b/PHPCI/Model/Build/LocalBuild.php
index 6edac398..f66dbdd3 100644
--- a/PHPCI/Model/Build/LocalBuild.php
+++ b/PHPCI/Model/Build/LocalBuild.php
@@ -44,7 +44,7 @@ class LocalBuild extends Build
 			}
 		}
 		else {
-			$builder->executeCommand(sprintf("cp -Rf %s %s/", $reference, $buildPath));
+			$builder->executeCommand('cp -Rf "%s" "%s/"', $reference, $buildPath);
 		}
 
 		return true;
diff --git a/PHPCI/Model/Build/RemoteGitBuild.php b/PHPCI/Model/Build/RemoteGitBuild.php
index 7df16b08..db72a3d8 100644
--- a/PHPCI/Model/Build/RemoteGitBuild.php
+++ b/PHPCI/Model/Build/RemoteGitBuild.php
@@ -48,7 +48,7 @@ abstract class RemoteGitBuild extends Build
 
 	protected function cloneByHttp(Builder $builder, $to)
 	{
-		return $builder->executeCommand('git clone -b ' .$this->getBranch() . ' ' .$this->getCloneUrl().' '.$to);
+		return $builder->executeCommand('git clone -b %s %s "%s"', $this->getBranch(), $this->getCloneUrl(), $to);
 	}
 
 	protected function cloneBySsh(Builder $builder, $to)
@@ -59,7 +59,7 @@ abstract class RemoteGitBuild extends Build
 		chmod($keyFile, 0600);
 
 		// Use the key file to do an SSH clone:
-		$success = $builder->executeCommand('ssh-agent ssh-add '.$keyFile.' && git clone -b ' .$build->getBranch() . ' ' .$this->getCloneUrl().' '.$to.' && ssh-agent -k');
+		$success = $builder->executeCommand('ssh-agent ssh-add "%s" && git clone -b %s %s "%s" && ssh-agent -k', $keyFile, $build->getBranch(), $this->getCloneUrl(), $to);
 		
 		// Remove the key file:
 		unlink($keyFile);
diff --git a/PHPCI/Plugin/Composer.php b/PHPCI/Plugin/Composer.php
index ac73f7de..1760fb98 100644
--- a/PHPCI/Plugin/Composer.php
+++ b/PHPCI/Plugin/Composer.php
@@ -17,6 +17,6 @@ class Composer implements \PHPCI\Plugin
 
 	public function execute()
 	{
-		return $this->phpci->executeCommand(PHPCI_DIR . 'composer.phar --prefer-dist --working-dir=' . $this->directory . ' ' . $this->action);
+		return $this->phpci->executeCommand(PHPCI_DIR . 'composer.phar --prefer-dist --working-dir="%s" %s', $this->directory, $this->action);
 	}
 }
\ No newline at end of file
diff --git a/PHPCI/Plugin/PhpCodeSniffer.php b/PHPCI/Plugin/PhpCodeSniffer.php
index 9b7095c3..aeef9a6a 100644
--- a/PHPCI/Plugin/PhpCodeSniffer.php
+++ b/PHPCI/Plugin/PhpCodeSniffer.php
@@ -17,8 +17,9 @@ class PhpCodeSniffer implements \PHPCI\Plugin
 
 	public function execute()
 	{
-		if(count($this->phpci->ignore))
-		{
+		$ignore = '';
+		
+		if(count($this->phpci->ignore)) {
 			$ignore = array_map(function($item)
 			{
 				return substr($item, -1) == '/' ? $item . '*' : $item . '/*';
@@ -27,6 +28,6 @@ class PhpCodeSniffer implements \PHPCI\Plugin
 			$ignore = ' --ignore=' . implode(',', $ignore);
 		}
 
-		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpcs --standard=' . $this->standard . $ignore. ' ' . $this->phpci->buildPath);
+		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpcs --standard=%s %s "%s"', $this->standard, $ignore, $this->phpci->buildPath);
 	}
 }
\ No newline at end of file
diff --git a/PHPCI/Plugin/PhpCpd.php b/PHPCI/Plugin/PhpCpd.php
index a57e8aa1..c4adbf0a 100644
--- a/PHPCI/Plugin/PhpCpd.php
+++ b/PHPCI/Plugin/PhpCpd.php
@@ -17,6 +17,7 @@ class PhpCpd implements \PHPCI\Plugin
 
 	public function execute()
 	{
+		$ignore = '';
 		if(count($this->phpci->ignore))
 		{
 			$ignore = array_map(function($item)
@@ -27,6 +28,6 @@ class PhpCpd implements \PHPCI\Plugin
 			$ignore = implode('', $ignore);
 		}
 
-		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpcpd' . $ignore . ' ' . $this->phpci->buildPath);
+		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpcpd %s "%s"', $ignore, $this->phpci->buildPath);
 	}
 }
\ No newline at end of file
diff --git a/PHPCI/Plugin/PhpMessDetector.php b/PHPCI/Plugin/PhpMessDetector.php
index 3a43415c..57af0eb5 100644
--- a/PHPCI/Plugin/PhpMessDetector.php
+++ b/PHPCI/Plugin/PhpMessDetector.php
@@ -13,6 +13,8 @@ class PhpMessDetector implements \PHPCI\Plugin
 
 	public function execute()
 	{
+		$ignore = '';
+		
 		if(count($this->phpci->ignore))
 		{
 			$ignore = array_map(function($item)
@@ -23,6 +25,6 @@ class PhpMessDetector implements \PHPCI\Plugin
 			$ignore = ' --exclude ' . implode(',', $ignore);
 		}
 
-		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpmd ' . $this->phpci->buildPath . ' text codesize,unusedcode,naming' . $ignore);
+		return $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpmd "%s" text codesize,unusedcode,naming %s', $this->phpci->buildPath, $ignore);
 	}
 }
\ No newline at end of file
diff --git a/PHPCI/Plugin/PhpUnit.php b/PHPCI/Plugin/PhpUnit.php
index fbce90db..5b057c01 100644
--- a/PHPCI/Plugin/PhpUnit.php
+++ b/PHPCI/Plugin/PhpUnit.php
@@ -62,7 +62,7 @@ class PhpUnit implements \PHPCI\Plugin
 				$curdir = getcwd();
 				chdir($this->phpci->buildPath.'/'.$this->runFrom);
 			}
-			$success = $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpunit ' . $this->args . ' -c ' . $this->phpci->buildPath . $configPath);
+			$success = $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpunit %s -c "%s"', $this->args, $this->phpci->buildPath . $configPath);
 			if ($this->runFrom) {
 				chdir($curdir);
 			}
@@ -78,7 +78,7 @@ class PhpUnit implements \PHPCI\Plugin
 		else {
 			$curdir = getcwd();
 			chdir($this->phpci->buildPath);
-			$success = $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpunit ' . $this->args . ' ' . $this->phpci->buildPath . $dirPath);
+			$success = $this->phpci->executeCommand(PHPCI_BIN_DIR . 'phpunit %s "%s"', $this->args, $this->phpci->buildPath . $dirPath);
 			chdir($curdir);
 			return $success;
 		}