diff --git a/src/Hook.lua b/src/Hook.lua
index 5765a12cb..cdb24d6f4 100644
--- a/src/Hook.lua
+++ b/src/Hook.lua
@@ -82,13 +82,19 @@ local validT =
 -- Checks for a valid hook name and stores it if valid.
 -- @param name The name of the hook.
 -- @param func The function to store with it.
-function M.register(name, func)
-   if (validT[name] ~= nil) then
-      validT[name] = func
+function M.register(name, func, append)
+  if (validT[name] ~= nil) then
+      -- set default for append to be backwards compatible
+      append = append or false
+      -- if append and validT[name] was set before, append. Otherwise, overwrite.
+      if append and validT[name] then
+         validT[name][#validT[name]+1] = func
+      else
+         validT[name] = {func}
+      end
    else
       LmodWarning{msg="w_Unknown_Hook",name = tostring(name)}
    end
-
 end
 
 --------------------------------------------------------------------------
@@ -97,7 +103,9 @@ end
 -- @return the results of the hook if it exists.
 function M.apply(name, ...)
    if (validT[name]) then
-      return validT[name](...)
+      for i=1,#validT[name] do
+         validT[name][i](...)
+      end
    end
 end