diff --git a/lib/awful/layout/init.lua.in b/lib/awful/layout/init.lua.in
index fec04ee36..bd9de0d47 100644
--- a/lib/awful/layout/init.lua.in
+++ b/lib/awful/layout/init.lua.in
@@ -43,13 +43,22 @@ function layout.inc(layouts, i, s)
     if t then
         local curlayout = layout.get(s)
         local curindex
-        local rev_layouts = {}
         for k, v in ipairs(layouts) do
             if v == curlayout then
                 curindex = k
                 break
             end
         end
+        if not curindex then
+            -- Safety net: handle cases where another reference of the layout
+            -- might be given (e.g. when (accidentally) cloning it).
+            for k, v in ipairs(layouts) do
+                if v.name == curlayout.name then
+                    curindex = k
+                    break
+                end
+            end
+        end
         if curindex then
             local newindex = util.cycle(#layouts, curindex + i)
             layout.set(layouts[newindex], t)