diff --git a/modules/update/update.module b/modules/update/update.module
index 33747ff474c027dafa09ae40c3531a4955c0f837..887078334c3d19018d21c9423e6ecddae7b9c42c 100644
--- a/modules/update/update.module
+++ b/modules/update/update.module
@@ -336,6 +336,16 @@ function update_get_available($refresh = FALSE) {
   return $available;
 }
 
+/**
+ * Implementation of hook_flush_caches().  The function update.php (among others)
+ * calls this hook to flush the caches.  Since we're running update.php, we are
+ * likely to install a new version of something, in which case, we want to check
+ * for available update data again.
+ */
+function update_flush_caches() {
+  return array('cache_update');
+}
+
 /**
  * Invalidates any cached data relating to update status.
  */