diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index bb872c7..7599602 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -461,7 +461,7 @@
 			{
 				$this->_field_data[$field]['postdata'] = $this->_reduce_array($validation_array, $row['keys']);
 			}
-			elseif (isset($validation_array[$field]) && $validation_array[$field] !== '')
+			elseif (isset($validation_array[$field]))
 			{
 				$this->_field_data[$field]['postdata'] = $validation_array[$field];
 			}
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index cda5d31..a3e1dc4 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -21,6 +21,7 @@
 -  Fixed a bug (#3771) - :doc:`Form Validation Library <libraries/form_validation>` was looking for a 'form_validation_' prefix when trying to translate field name labels.
 -  Fixed a bug (#3787) - :doc:`FTP Library <libraries/ftp>` method ``delete_dir()`` failed when the target has subdirectories.
 -  Fixed a bug (#3801) - :doc:`Output Library <libraries/output>` method ``_display_cache()`` incorrectly looked for the last modified time of a directory instead of the cache file.
+-  Fixed a bug (#3816) - :doc:`Form Validation Library <libraries/form_validation>` treated empty string values as non-existing ones.
 
 Version 3.0.0
 =============