diff --git a/control/Director.php b/control/Director.php
index 4b63a9092..dafa2340f 100644
--- a/control/Director.php
+++ b/control/Director.php
@@ -208,9 +208,8 @@ class Director implements TemplateGlobalProvider {
 		Requirements::set_backend(new Requirements_Backend());
 
 		// Handle absolute URLs
-		if (@parse_url($url, PHP_URL_HOST) != '') {
-			$bits = parse_url($url);
-			$_SERVER['HTTP_HOST'] = $bits['host'];
+		if ($host = parse_url($url, PHP_URL_HOST)) {
+			$_SERVER['HTTP_HOST'] = $host;
 			$url = Director::makeRelative($url);
 		}
 
diff --git a/dev/Backtrace.php b/dev/Backtrace.php
index 704381322..f77d3464b 100644
--- a/dev/Backtrace.php
+++ b/dev/Backtrace.php
@@ -90,7 +90,7 @@ class SS_Backtrace {
 		// Filter out arguments
 		foreach($bt as $i => $frame) {
 			$match = false;
-			if(@$bt[$i]['class']) {
+			if(!empty($bt[$i]['class'])) {
 				foreach(self::$ignore_function_args as $fnSpec) {
 					if(is_array($fnSpec) && $bt[$i]['class'] == $fnSpec[0] && $bt[$i]['function'] == $fnSpec[1]) {
 						$match = true;
diff --git a/dev/Debug.php b/dev/Debug.php
index 7755f26eb..0ed8a2027 100644
--- a/dev/Debug.php
+++ b/dev/Debug.php
@@ -419,7 +419,12 @@ class Debug {
 		$reporter = self::create_debug_view();
 		
 		// Coupling alert: This relies on knowledge of how the director gets its URL, it could be improved.
-		$httpRequest = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : @$_REQUEST['url'];
+		$httpRequest = null;
+		if(isset($_SERVER['REQUEST_URI'])) {
+			$httpRequest = $_SERVER['REQUEST_URI'];
+		} elseif(isset($_REQUEST['url'])) {
+			$httpRequest = $_REQUEST['url'];
+		}
 		if(isset($_SERVER['REQUEST_METHOD'])) $httpRequest = $_SERVER['REQUEST_METHOD'] . ' ' . $httpRequest;
 
 		$reporter->writeHeader($httpRequest);
diff --git a/dev/Log.php b/dev/Log.php
index ed2a65b0c..18223b5b5 100644
--- a/dev/Log.php
+++ b/dev/Log.php
@@ -94,7 +94,7 @@ class SS_Log {
 			// Add default context (shouldn't change until the actual log event happens)
 			foreach(static::$log_globals as $globalName => $keys) {
 				foreach($keys as $key) {
-					$val = @$GLOBALS[$globalName][$key];
+					$val = isset($GLOBALS[$globalName][$key]) ? $GLOBALS[$globalName][$key] : null;
 					static::$logger->setEventItem(sprintf('$%s[\'%s\']', $globalName, $key), $val);
 				}
 			}
@@ -167,8 +167,8 @@ class SS_Log {
 			$message = array(
 				'errno' => '',
 				'errstr' => $message,
-				'errfile' => @$lastTrace['file'],
-				'errline' => @$lastTrace['line'],
+				'errfile' => isset($lastTrace['file']) ? $lastTrace['file'] : null,
+				'errline' => isset($lastTrace['line']) ? $lastTrace['line'] : null,
 				'errcontext' => $trace
 			);
 		}
diff --git a/dev/LogErrorEmailFormatter.php b/dev/LogErrorEmailFormatter.php
index 370a6d5e5..3bb22eeac 100644
--- a/dev/LogErrorEmailFormatter.php
+++ b/dev/LogErrorEmailFormatter.php
@@ -63,8 +63,8 @@ class SS_LogErrorEmailFormatter implements Zend_Log_Formatter_Interface {
 		$relfile = Director::makeRelative($errfile);
 		if($relfile && $relfile[0] == '/') $relfile = substr($relfile, 1);
 		
-		$host = @$_SERVER['HTTP_HOST'];
-		$uri = @$_SERVER['REQUEST_URI'];
+		$host = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : null;
+		$uri = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : null;
 
 		$subject = "[$errorType] in $relfile:{$errline} (http://{$host}{$uri})";
 
diff --git a/dev/install/install.php5 b/dev/install/install.php5
index 575801b47..06c161542 100644
--- a/dev/install/install.php5
+++ b/dev/install/install.php5
@@ -362,11 +362,15 @@ class InstallRequirements {
 	 */
 	function findWebserver() {
 		// Try finding from SERVER_SIGNATURE or SERVER_SOFTWARE
-		$webserver = @$_SERVER['SERVER_SIGNATURE'];
-		if(!$webserver) $webserver = @$_SERVER['SERVER_SOFTWARE'];
+		if(!empty($_SERVER['SERVER_SIGNATURE'])) {
+			$webserver = $_SERVER['SERVER_SIGNATURE'];
+		} elseif(!empty($_SERVER['SERVER_SOFTWARE'])) {
+			$webserver = $_SERVER['SERVER_SOFTWARE'];
+		} else {
+			return false;
+		}
 
-		if($webserver) return strip_tags(trim($webserver));
-		else return false;
+		return strip_tags(trim($webserver));
 	}
 
 	/**
@@ -913,7 +917,7 @@ class InstallRequirements {
 			$this->testing($testDetails);
 			return true;
 		} else {
-			if(!@$result['cannotCreate']) {
+			if(empty($result['cannotCreate'])) {
 				$testDetails[2] .= ". Please create the database manually.";
 			} else {
 				$testDetails[2] .= " (user '$databaseConfig[username]' doesn't have CREATE DATABASE permissions.)";
@@ -972,7 +976,7 @@ class InstallRequirements {
 		$section = $testDetails[0];
 		$test = $testDetails[1];
 
-		$this->tests[$section][$test] = array("error", @$testDetails[2]);
+		$this->tests[$section][$test] = array("error", isset($testDetails[2]) ? $testDetails[2] : null);
 		$this->errors[] = $testDetails;
 	}
 
@@ -980,7 +984,7 @@ class InstallRequirements {
 		$section = $testDetails[0];
 		$test = $testDetails[1];
 
-		$this->tests[$section][$test] = array("warning", @$testDetails[2]);
+		$this->tests[$section][$test] = array("warning", isset($testDetails[2]) ? $testDetails[2] : null);
 		$this->warnings[] = $testDetails;
 	}
 
diff --git a/docs/en/howto/phpunit-configuration.md b/docs/en/howto/phpunit-configuration.md
index fde20de6d..4ac184feb 100644
--- a/docs/en/howto/phpunit-configuration.md
+++ b/docs/en/howto/phpunit-configuration.md
@@ -71,7 +71,7 @@ Example `mysite/_config.php`:
 	// Customized configuration for running with different database settings.
 	// Ensure this code comes after ConfigureFromEnv.php
 	if(Director::isDev()) {
-		if($db = @$_GET['db']) {
+		if(isset($_GET['db']) && ($db = $_GET['db'])) {
 			global $databaseConfig;
 			if($db == 'sqlite3') $databaseConfig['type'] = 'SQLite3Database';
 		}
diff --git a/forms/Form.php b/forms/Form.php
index 7e7398ef2..9f3e6361f 100644
--- a/forms/Form.php
+++ b/forms/Form.php
@@ -651,7 +651,7 @@ class Form extends RequestHandler {
 	 * @return String
 	 */
 	public function getAttribute($name) {
-		return @$this->attributes[$name];
+		if(isset($this->attributes[$name])) return $this->attributes[$name];
 	}
 
 	public function getAttributes() {
diff --git a/forms/FormField.php b/forms/FormField.php
index 16abd410b..e0468164f 100644
--- a/forms/FormField.php
+++ b/forms/FormField.php
@@ -361,7 +361,7 @@ class FormField extends RequestHandler {
 	 */
 	public function getAttribute($name) {
 		$attrs = $this->getAttributes();
-		return @$attrs[$name];
+		if(isset($attrs[$name])) return $attrs[$name];
 	}
 	
 	/**
diff --git a/forms/gridfield/GridField.php b/forms/gridfield/GridField.php
index 33d23100d..a252c108e 100644
--- a/forms/gridfield/GridField.php
+++ b/forms/gridfield/GridField.php
@@ -591,7 +591,8 @@ class GridField extends FormField {
 	public function gridFieldAlterAction($data, $form, SS_HTTPRequest $request) {
 		$html = '';
 		$data = $request->requestVars();
-		$fieldData = @$data[$this->getName()];
+		$name = $this->getName();
+		$fieldData = isset($data[$name]) ? $data[$name] : null;
 
 		// Update state from client
 		$state = $this->getState(false);
diff --git a/model/Database.php b/model/Database.php
index 699bb9625..287538614 100644
--- a/model/Database.php
+++ b/model/Database.php
@@ -214,14 +214,16 @@ abstract class SS_Database {
 		foreach($this->schemaUpdateTransaction as $tableName => $changes) {
 			switch($changes['command']) {
 				case 'create':
-				$this->createTable($tableName, $changes['newFields'], $changes['newIndexes'], $changes['options'],
-					@$changes['advancedOptions']);
+					$this->createTable($tableName, $changes['newFields'], $changes['newIndexes'], $changes['options'],
+						isset($changes['advancedOptions']) ? $changes['advancedOptions'] : null
+					);
 					break;
 				
 				case 'alter':
 					$this->alterTable($tableName, $changes['newFields'], $changes['newIndexes'],
-					$changes['alteredFields'], $changes['alteredIndexes'], $changes['alteredOptions'],
-					@$changes['advancedOptions']);
+						$changes['alteredFields'], $changes['alteredIndexes'], $changes['alteredOptions'],
+						isset($changes['advancedOptions']) ? $changes['advancedOptions'] : null
+					);
 					break;
 			}
 		}
diff --git a/model/HTMLValue.php b/model/HTMLValue.php
index e06d3e5d7..fc8d06a19 100644
--- a/model/HTMLValue.php
+++ b/model/HTMLValue.php
@@ -73,10 +73,14 @@ class SS_HTMLValue extends ViewableData {
 		// This behaviour is apparently XML spec, but we don't want this because it messes up the HTML
 		$content = str_replace(chr(13), '', $content);
 
-		return @$this->getDocument()->loadHTML(
+		$errorState = libxml_use_internal_errors(true);
+		$result = $this->getDocument()->loadHTML(
 			'<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head>' .
 			"<body>$content</body></html>"
 		);
+		libxml_clear_errors();
+		libxml_use_internal_errors($errorState);
+		return $result;
 	}
 
 	/**
diff --git a/tests/security/BasicAuthTest.php b/tests/security/BasicAuthTest.php
index 4920e4284..f432af400 100644
--- a/tests/security/BasicAuthTest.php
+++ b/tests/security/BasicAuthTest.php
@@ -26,8 +26,8 @@ class BasicAuthTest extends FunctionalTest {
 	}
 
 	public function testBasicAuthEnabledWithoutLogin() {
-		$origUser = @$_SERVER['PHP_AUTH_USER'];
-		$origPw = @$_SERVER['PHP_AUTH_PW'];
+		$origUser = isset($_SERVER['PHP_AUTH_USER']) ? $_SERVER['PHP_AUTH_USER'] : null;
+		$origPw = isset($_SERVER['PHP_AUTH_PW']) ? $_SERVER['PHP_AUTH_PW'] : null;
 		
 		unset($_SERVER['PHP_AUTH_USER']);
 		unset($_SERVER['PHP_AUTH_PW']);
@@ -40,8 +40,8 @@ class BasicAuthTest extends FunctionalTest {
 	}
 	
 	public function testBasicAuthDoesntCallActionOrFurtherInitOnAuthFailure() {
-		$origUser = @$_SERVER['PHP_AUTH_USER'];
-		$origPw = @$_SERVER['PHP_AUTH_PW'];
+		$origUser = isset($_SERVER['PHP_AUTH_USER']) ? $_SERVER['PHP_AUTH_USER'] : null;
+		$origPw = isset($_SERVER['PHP_AUTH_PW']) ? $_SERVER['PHP_AUTH_PW'] : null;
 		
 		unset($_SERVER['PHP_AUTH_USER']);
 		unset($_SERVER['PHP_AUTH_PW']);
@@ -60,8 +60,8 @@ class BasicAuthTest extends FunctionalTest {
 	}
 
 	public function testBasicAuthEnabledWithPermission() {
-		$origUser = @$_SERVER['PHP_AUTH_USER'];
-		$origPw = @$_SERVER['PHP_AUTH_PW'];
+		$origUser = isset($_SERVER['PHP_AUTH_USER']) ? $_SERVER['PHP_AUTH_USER'] : null;
+		$origPw = isset($_SERVER['PHP_AUTH_PW']) ? $_SERVER['PHP_AUTH_PW'] : null;
 		
 		$_SERVER['PHP_AUTH_USER'] = 'user-in-mygroup@test.com';
 		$_SERVER['PHP_AUTH_PW'] = 'wrongpassword';
@@ -83,8 +83,8 @@ class BasicAuthTest extends FunctionalTest {
 	}
 	
 	public function testBasicAuthEnabledWithoutPermission() {
-		$origUser = @$_SERVER['PHP_AUTH_USER'];
-		$origPw = @$_SERVER['PHP_AUTH_PW'];
+		$origUser = isset($_SERVER['PHP_AUTH_USER']) ? $_SERVER['PHP_AUTH_USER'] : null;
+		$origPw = isset($_SERVER['PHP_AUTH_PW']) ? $_SERVER['PHP_AUTH_PW'] : null;
 		
 		$_SERVER['PHP_AUTH_USER'] = 'user-without-groups@test.com';
 		$_SERVER['PHP_AUTH_PW'] = 'wrongpassword';