diff --git a/dev/Backtrace.php b/dev/Backtrace.php
index 186641ead..45531f70e 100644
--- a/dev/Backtrace.php
+++ b/dev/Backtrace.php
@@ -173,7 +173,7 @@ class SS_Backtrace {
 				}
 				$result .= "<li><b>" . htmlentities($name, ENT_COMPAT, 'UTF-8') . "</b>\n<br />\n";
 				$result .= isset($item['line']) ? "Line $item[line] of " : '';
-				$result .=  isset($item['file']) ? htmlentities(basename($item['file'])) : ''; 
+				$result .=  isset($item['file']) ? htmlentities(basename($item['file']), ENT_COMPAT, 'UTF-8') : ''; 
 				$result .= "</li>\n";
 			}
 		}
diff --git a/dev/Debug.php b/dev/Debug.php
index f568a8f63..8c30fc9e0 100644
--- a/dev/Debug.php
+++ b/dev/Debug.php
@@ -141,7 +141,7 @@ class Debug {
 			$val = '(bool) ' . $val;
 		} else {
 			if(!Director::is_cli() && !Director::is_ajax()) {
-				$val = "<pre style=\"font-family: Courier new\">" . htmlentities($val) . "</pre>\n";
+				$val = "<pre style=\"font-family: Courier new\">" . htmlentities($val, ENT_COMPAT, 'UTF-8') . "</pre>\n";
 			}
 		}
 
diff --git a/dev/DebugView.php b/dev/DebugView.php
index 9014e3be6..fea85a309 100644
--- a/dev/DebugView.php
+++ b/dev/DebugView.php
@@ -126,7 +126,7 @@ class DebugView extends Object {
 	 */
 	public function writeError($httpRequest, $errno, $errstr, $errfile, $errline, $errcontext) {
 		$errorType = self::$error_types[$errno];
-		$httpRequestEnt = htmlentities($httpRequest);
+		$httpRequestEnt = htmlentities($httpRequest, ENT_COMPAT, 'UTF-8');
 		echo '<div class="info ' . $errorType['class'] . '">';
 		echo "<h1>[" . $errorType['title'] . '] ' . strip_tags($errstr) . "</h1>";
 		echo "<h3>$httpRequestEnt</h3>";
diff --git a/dev/install/install.php5 b/dev/install/install.php5
index bfc21a0c5..48599010e 100644
--- a/dev/install/install.php5
+++ b/dev/install/install.php5
@@ -469,7 +469,7 @@ class InstallRequirements {
 		if($this->errors) {
 			echo "<p>The following problems are preventing me from installing SilverStripe CMS:</p>\n\n";
 			foreach($this->errors as $error) {
-				echo "<li>" . htmlentities(implode(", ", $error)) . "</li>\n";
+				echo "<li>" . htmlentities(implode(", ", $error), ENT_COMPAT, 'UTF-8') . "</li>\n";
 			}
 		}
 	}
@@ -480,7 +480,7 @@ class InstallRequirements {
 			$id = strtolower(str_replace(' ', '_', $section));
 			echo "<table id=\"{$id}_results\" class=\"testResults\" width=\"100%\">";
 			foreach($tests as $test => $result) {
-				echo "<tr class=\"$result[0]\"><td>$test</td><td>" . nl2br(htmlentities($result[1])) . "</td></tr>";
+				echo "<tr class=\"$result[0]\"><td>$test</td><td>" . nl2br(htmlentities($result[1]), ENT_COMPAT, 'UTF-8') . "</td></tr>";
 			}
 			echo "</table>";
 
@@ -502,7 +502,7 @@ class InstallRequirements {
 								break;
 						}
 					}
-					$output .= "<tr class=\"$result[0]\"><td>$test</td><td>" . nl2br(htmlentities($result[1])) . "</td></tr>";
+					$output .= "<tr class=\"$result[0]\"><td>$test</td><td>" . nl2br(htmlentities($result[1], ENT_COMPAT, 'UTF-8')) . "</td></tr>";
 				}
 				$className = "good";
 				$text = "All Requirements Pass";