diff --git a/src/Database/Dialect/PostgresDialectTrait.php b/src/Database/Dialect/PostgresDialectTrait.php
index 1416bfd72f3..ea26f4bb3c9 100644
--- a/src/Database/Dialect/PostgresDialectTrait.php
+++ b/src/Database/Dialect/PostgresDialectTrait.php
@@ -101,10 +101,15 @@ protected function _transformFunctionExpression(FunctionExpression $expression)
 				break;
 			case 'DATEDIFF':
 				$expression
-					->name('')
+					->name('ABS')
 					->type('-')
 					->iterateParts(function ($p) {
-						return new FunctionExpression('DATE', [$p['value']], [$p['type']]);
+						if( is_string($p) )
+							$p = [ 'value' => [$p => 'literal'], 'type' => null ];
+						else
+							$p['value'] = [$p['value']];
+
+						return new FunctionExpression('DATE', $p['value'], [$p['type']]);
 					});
 				break;
 			case 'CURRENT_DATE':