diff --git a/code/PostgreSQLDatabase.php b/code/PostgreSQLDatabase.php
index 6e794e9..e6b247a 100644
--- a/code/PostgreSQLDatabase.php
+++ b/code/PostgreSQLDatabase.php
@@ -420,6 +420,7 @@ class PostgreSQLDatabase extends SS_Database {
 		} else {
 			$comp = ($caseSensitive === true) ? 'LIKE' : 'ILIKE';
 			if($negate) $comp = 'NOT ' . $comp;
+			$field.='::text';
 		}
 
 		if($parameterised) {