diff --git a/src/Dibi/Drivers/MySqliDriver.php b/src/Dibi/Drivers/MySqliDriver.php
index 8640f02a..9853d4e1 100644
--- a/src/Dibi/Drivers/MySqliDriver.php
+++ b/src/Dibi/Drivers/MySqliDriver.php
@@ -317,7 +317,7 @@ class MySqliDriver implements Dibi\Driver
 		if ($value->y || $value->m || $value->d) {
 			throw new Dibi\NotSupportedException('Only time interval is supported.');
 		}
-		return $value->format('%r%H:%I:%S.%f');
+		return $value->format("'%r%H:%I:%S.%f'");
 	}