diff --git a/phpBB/includes/acp/acp_board.php b/phpBB/includes/acp/acp_board.php
index 8e571de379..c3fb160db8 100644
--- a/phpBB/includes/acp/acp_board.php
+++ b/phpBB/includes/acp/acp_board.php
@@ -510,6 +510,25 @@ class acp_board
 			}
 		}
 
+		if ($mode == 'avatar' && $cfg_array['allow_avatar_upload'])
+		{
+			$filesystem = $phpbb_container->get('filesystem');
+
+			// If avatar uploading is enabled but the path setting is empty,
+			// config variable validation is bypassed. Catch the case here
+			if (!$cfg_array['avatar_path'])
+			{
+				$error[] = $language->lang('AVATAR_NO_UPLOAD_PATH');
+			}
+			// Not existing or writable path will be caught on submit by config vars validation
+			// Display the warning if the directory was changed on the server afterwards
+			else if (!$submit &&
+				(!$filesystem->exists($phpbb_root_path . $cfg_array['avatar_path']) || !$filesystem->is_writable($phpbb_root_path . $cfg_array['avatar_path'])))
+			{
+				$error[] = $language->lang('AVATAR_NO_UPLOAD_DIR');
+			}
+		}
+
 		// We validate the complete config if wished
 		validate_config_vars($display_vars['vars'], $cfg_array, $error);
 
diff --git a/phpBB/language/en/common.php b/phpBB/language/en/common.php
index 3f8117b7af..fefb7dafb6 100644
--- a/phpBB/language/en/common.php
+++ b/phpBB/language/en/common.php
@@ -110,6 +110,8 @@ $lang = array_merge($lang, array(
 	'AVATAR_NOT_UPLOADED'			=> 'Avatar could not be uploaded.',
 	'AVATAR_NO_TEMP_DIR'			=> 'Temporary folder could not be found or is not writable.',
 	'AVATAR_NO_SIZE'				=> 'The width or height of the linked avatar could not be determined. Please enter them manually.',
+	'AVATAR_NO_UPLOAD_DIR'			=> 'Avatar storage path does not exist or is not writable.',
+	'AVATAR_NO_UPLOAD_PATH'			=> 'Avatar uploading is enabled but avatar storage path is not set.',
 	'AVATAR_PARTIAL_UPLOAD'			=> 'The specified file was only partially uploaded.',
 	'AVATAR_PHP_SIZE_NA'			=> 'The avatar’s filesize is too large.<br />The maximum allowed filesize set in php.ini could not be determined.',
 	'AVATAR_PHP_SIZE_OVERRUN'		=> 'The avatar’s filesize is too large. The maximum allowed upload size is %1$d %2$s.<br />Please note this is set in php.ini and cannot be overridden.',