diff --git a/phpBB/includes/functions_content.php b/phpBB/includes/functions_content.php
index f851309a1e..0d367f953f 100644
--- a/phpBB/includes/functions_content.php
+++ b/phpBB/includes/functions_content.php
@@ -822,7 +822,7 @@ function parse_attachments($forum_id, &$message, &$attachments, &$update_count,
 		}
 
 		$filesize = $attachment['filesize'];
-		$size_lang = ($filesize >= 1048576) ? $user->lang['MB'] : ( ($filesize >= 1024) ? $user->lang['KB'] : $user->lang['BYTES'] );
+		$size_lang = ($filesize >= 1048576) ? $user->lang['MIB'] : (($filesize >= 1024) ? $user->lang['KIB'] : $user->lang['BYTES']);
 		$filesize = get_formatted_filesize($filesize, false);
 
 		$comment = bbcode_nl2br(censor_text($attachment['attach_comment']));
diff --git a/phpBB/includes/functions_upload.php b/phpBB/includes/functions_upload.php
index e75db00414..ca4f51c12f 100644
--- a/phpBB/includes/functions_upload.php
+++ b/phpBB/includes/functions_upload.php
@@ -386,7 +386,7 @@ class filespec
 		// Filesize is too big or it's 0 if it was larger than the maxsize in the upload form
 		if ($this->upload->max_filesize && ($this->get('filesize') > $this->upload->max_filesize || $this->filesize == 0))
 		{
-			$size_lang = ($this->upload->max_filesize >= 1048576) ? $user->lang['MB'] : (($this->upload->max_filesize >= 1024) ? $user->lang['KB'] : $user->lang['BYTES'] );
+			$size_lang = ($this->upload->max_filesize >= 1048576) ? $user->lang['MIB'] : (($this->upload->max_filesize >= 1024) ? $user->lang['KIB'] : $user->lang['BYTES'] );
 			$max_filesize = get_formatted_filesize($this->upload->max_filesize, false);
 	
 			$this->error[] = sprintf($user->lang[$this->upload->error_prefix . 'WRONG_FILESIZE'], $max_filesize, $size_lang);
@@ -777,7 +777,7 @@ class fileupload
 			break;
 
 			case 2:
-				$size_lang = ($this->max_filesize >= 1048576) ? $user->lang['MB'] : (($this->max_filesize >= 1024) ? $user->lang['KB'] : $user->lang['BYTES'] );
+				$size_lang = ($this->max_filesize >= 1048576) ? $user->lang['MIB'] : (($this->max_filesize >= 1024) ? $user->lang['KIB'] : $user->lang['BYTES']);
 				$max_filesize = get_formatted_filesize($this->max_filesize, false);
 
 				$error = sprintf($user->lang[$this->error_prefix . 'WRONG_FILESIZE'], $max_filesize, $size_lang);
@@ -813,7 +813,7 @@ class fileupload
 		// Filesize is too big or it's 0 if it was larger than the maxsize in the upload form
 		if ($this->max_filesize && ($file->get('filesize') > $this->max_filesize || $file->get('filesize') == 0))
 		{
-			$size_lang = ($this->max_filesize >= 1048576) ? $user->lang['MB'] : (($this->max_filesize >= 1024) ? $user->lang['KB'] : $user->lang['BYTES'] );
+			$size_lang = ($this->max_filesize >= 1048576) ? $user->lang['MIB'] : (($this->max_filesize >= 1024) ? $user->lang['KIB'] : $user->lang['BYTES']);
 			$max_filesize = get_formatted_filesize($this->max_filesize, false);
 
 			$file->error[] = sprintf($user->lang[$this->error_prefix . 'WRONG_FILESIZE'], $max_filesize, $size_lang);