diff --git a/phpgwapi/inc/class.config.inc.php b/phpgwapi/inc/class.config.inc.php
index 42a04ab9eb..a473da2a97 100755
--- a/phpgwapi/inc/class.config.inc.php
+++ b/phpgwapi/inc/class.config.inc.php
@@ -218,6 +218,11 @@ class config
 				$value = $row['config_value'];
 
 				$test = @unserialize($value);
+				if($test === false)
+				{
+					// manually retrieve the string lengths of the serialized array if unserialize failed
+					$test = @unserialize(preg_replace('!s:(\d+):"(.*?)";!se', "'s:'.mb_strlen('$2','8bit').':\"$2\";'", $value));
+				}
 
 				$config[$name] = is_array($test) ? $test : $value;
 			}
diff --git a/phpgwapi/inc/class.preferences.inc.php b/phpgwapi/inc/class.preferences.inc.php
index f0cb369edd..1c97704a2a 100644
--- a/phpgwapi/inc/class.preferences.inc.php
+++ b/phpgwapi/inc/class.preferences.inc.php
@@ -272,6 +272,11 @@ class preferences
 			// The following replacement is required for PostgreSQL to work
 			$app = trim($row['preference_app']);
 			$value = unserialize($row['preference_value']);
+			if($value === false)
+			{
+				// manually retrieve the string lengths of the serialized array if unserialize failed
+				$value = unserialize(preg_replace('!s:(\d+):"(.*?)";!se', "'s:'.mb_strlen('$2','8bit').':\"$2\";'", $row['preference_value']));
+			}
 			$this->unquote($value);
 			if (!is_array($value))
 			{