diff --git a/libraries.install b/libraries.install
index ac9e652..b210b98 100644
--- a/libraries.install
+++ b/libraries.install
@@ -10,7 +10,7 @@
  */
 function libraries_schema() {
   $schema['cache_libraries'] = drupal_get_schema_unprocessed('system', 'cache');
-  $schema['cache_libraries']['description'] = 'Cache table to store library information';
+  $schema['cache_libraries']['description'] = 'Cache table to store library information.';
   return $schema;
 }
 
@@ -18,8 +18,10 @@ function libraries_schema() {
  * Create the 'cache_libraries' table.
  */
 function libraries_update_7200() {
+  // Note that previous versions of this function created the table with a
+  // different table comment.
   if (!db_table_exists('cache_libraries')) {
-    $specs = drupal_get_schema_unprocessed('system', 'cache');
-    db_create_table('cache_libraries', $specs);
+    $specs = libraries_schema();
+    db_create_table('cache_libraries', $specs['cache_libraries']);
   }
 }