diff --git a/mod/scorm/datamodels/aicclib.php b/mod/scorm/datamodels/aicclib.php
index 2a3839305c9..b204d208c6e 100644
--- a/mod/scorm/datamodels/aicclib.php
+++ b/mod/scorm/datamodels/aicclib.php
@@ -411,7 +411,7 @@ function scorm_get_toc($user,$scorm,$liststyle,$currentorg='',$scoid='',$mode='n
                 }
                 $result->toc .= '<a href="javascript:expandCollide(\'img'.$sublist.'\',\'s'.$sublist.'\','.$nextsco->id.');"><img id="img'.$sublist.'" src="'.$scormpixdir.'/'.$icon.'.gif" alt="'.$strexpand.'" title="'.$strexpand.'"/></a>';
             } else if ($isvisible) {
-                $result->toc .= '<img src="'.$scormpixdir.'/spacer.gif" />';
+                $result->toc .= '<img src="'.$scormpixdir.'/spacer.gif" alt="spacer" />';
             }
             if (empty($sco->title)) {
                 $sco->title = $sco->identifier;
diff --git a/mod/scorm/datamodels/scorm_12lib.php b/mod/scorm/datamodels/scorm_12lib.php
index 185b029e8f8..c6610f6bfad 100644
--- a/mod/scorm/datamodels/scorm_12lib.php
+++ b/mod/scorm/datamodels/scorm_12lib.php
@@ -215,7 +215,7 @@ function scorm_get_toc($user,$scorm,$liststyle,$currentorg='',$scoid='',$mode='n
                 }
                $result->toc .= '<a href="javascript:expandCollide(\'img'.$sublist.'\',\'s'.$sublist.'\','.$nextsco->id.');"><img id="img'.$sublist.'" src="'.$scormpixdir.'/'.$icon.'.gif" alt="'.$strexpand.'" title="'.$strexpand.'"/></a>';
             } else if ($isvisible) {
-                $result->toc .= '<img src="'.$scormpixdir.'/spacer.gif" />';
+                $result->toc .= '<img src="'.$scormpixdir.'/spacer.gif" alt="spacer"/>';
             }
             if (empty($sco->title)) {
                 $sco->title = $sco->identifier;
diff --git a/mod/scorm/datamodels/scorm_13lib.php b/mod/scorm/datamodels/scorm_13lib.php
index 2ab57227718..74f295de6f8 100644
--- a/mod/scorm/datamodels/scorm_13lib.php
+++ b/mod/scorm/datamodels/scorm_13lib.php
@@ -107,7 +107,7 @@ function scorm_get_toc($user,$scorm,$liststyle,$currentorg='',$scoid='',$mode='n
                 $result->toc .= "\t\t".'<li><a href="javascript:expandCollide(\'img'.$sublist.'\',\'s'.$sublist.'\','.$nextsco->id.');">'.
                                 '<img id="img'.$sublist.'" src="'.$scormpixdir.'/'.$icon.'.gif" alt="'.$strexpand.'" title="'.$strexpand.'"/></a>';
             } else if ($isvisible) {
-                $result->toc .= "\t\t".'<li><img src="'.$scormpixdir.'/spacer.gif" />';
+                $result->toc .= "\t\t".'<li><img src="'.$scormpixdir.'/spacer.gif" alt="spacer" />';
             }
             if (empty($sco->title)) {
                 $sco->title = $sco->identifier;