diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 152f8f6..4d23e4e 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -348,7 +348,10 @@
 
 		if (($result = $this->db->query($sql)) !== FALSE)
 		{
-			isset($this->db->data_cache['table_names']) && $this->db->data_cache['table_names'][] = $table;
+			if (isset($this->db->data_cache['table_names']))
+			{
+				$this->db->data_cache['table_names'][] = $table;
+			}
 
 			// Most databases don't support creating indexes from within the CREATE TABLE statement
 			if ( ! empty($this->keys))
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index af32fe8..aa0eae7 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -17,6 +17,7 @@
 -  Fixed a bug (#5561) - :doc:`Database Library <database/index>` didn't allow SSL connection configuration with only the 'ssl_verify' option when using the 'mysqli' driver.
 -  Fixed a bug (#5545) - :doc:`Session Library <libraries/sessions>` crashed due to a caching-related error with the 'files' driver.
 -  Fixed a bug (#5571) - :doc:`XML-RPC Library <libraries/xmlrpc>` had a typo that triggered an ``E_WARNING`` message on PHP 7.2.
+-  Fixed a bug (#5587) - :doc:`Database Forge <database/forge>` method ``create_table()`` generated an ``E_WARNING`` message.
 
 Version 3.1.9
 =============