diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 49d3cda..8cbbfa1 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -255,7 +255,7 @@
 	{
 		$sql = 'SELECT "RDB$RELATION_NAME" FROM "RDB$RELATIONS" WHERE "RDB$RELATION_NAME" NOT LIKE \'RDB$%\' AND "RDB$RELATION_NAME" NOT LIKE \'MON$%\'';
 
-		if ($prefix_limit !== FALSE && $this->dbprefix != '')
+		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
 			return $sql.' AND "RDB$RELATION_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
diff --git a/system/database/drivers/interbase/interbase_forge.php b/system/database/drivers/interbase/interbase_forge.php
index c850656..5470179 100644
--- a/system/database/drivers/interbase/interbase_forge.php
+++ b/system/database/drivers/interbase/interbase_forge.php
@@ -195,7 +195,7 @@
 
 		$sql .= " {$column_definition}";
 
-		if ($default_value != '')
+		if ($default_value !== '')
 		{
 			$sql .= " DEFAULT \"{$default_value}\"";
 		}
@@ -209,7 +209,7 @@
 			$sql .= ' NOT NULL';
 		}
 
-		if ($after_field != '')
+		if ($after_field !== '')
 		{
 			$sql .= ' AFTER ' . $this->db->protect_identifiers($after_field);
 		}