diff --git a/doc/manual/multifit_3sfd.dox b/doc/manual/multifit_3sfd.dox
index 90c0d56a69..94a3d70d84 100644
--- a/doc/manual/multifit_3sfd.dox
+++ b/doc/manual/multifit_3sfd.dox
@@ -317,7 +317,7 @@ may require the protein to be treated flexibly, so that it can deform to more
 closely fit in the density. Such flexible fitting is not performed by MultiFit,
 but the MultiFit-generated models can be passed to a flexible fitting program
 for further refinement. Two such programs are
-\external{https://salilab.org/Flex-EM/,Flex-EM} and
-\external{http://www.ks.uiuc.edu/Research/mdff/,MDFF}.
+\external{https://flex-em.topf-group.com/,Flex-EM} and
+\external{https://www.ks.uiuc.edu/Research/mdff/,MDFF}.
 
 */