diff --git a/lib/awful/layout/suit/magnifier.lua.in b/lib/awful/layout/suit/magnifier.lua.in
index ee1847621..f0a7d3268 100644
--- a/lib/awful/layout/suit/magnifier.lua.in
+++ b/lib/awful/layout/suit/magnifier.lua.in
@@ -26,28 +26,27 @@ local function magnifier(_, screen)
     local focus = capi.client.focus
     local t = tag.selected(screen)
     local mwfact = tag.getmwfact(t)
+    local fidx -- Focus client index in cls table
+
+    -- Check that the focused window is on the right screen
+    if focus and focus.screen ~= screen then focus = nil end
 
     if not focus and #cls > 0 then
         focus = cls[1]
+        fidx = 1
     end
 
     -- Abort if no clients are present
-    if not focus then
-        return
-    end
-
-    -- Find parent of this window, if it has one.
-    while focus.transient_for do
-        focus = focus.transient_for
-    end
+    if not focus then return end
 
     -- If focused window is not tiled, take the first one which is tiled.
     if client.floating.get(focus) then
         focus = cls[1]
+        fidx = 1
     end
 
     local geometry = {}
-    if #cls - 1 > 0 then
+    if #cls > 1 then
         geometry.width = area.width * math.sqrt(mwfact)
         geometry.height = area.height * math.sqrt(mwfact)
         geometry.x = area.x + (area.width - geometry.width) / 2
@@ -61,17 +60,19 @@ local function magnifier(_, screen)
     focus:geometry(geometry)
     focus:raise()
 
-    if #cls - 1 > 0 then
+    if #cls > 1 then
         geometry.x = area.x
         geometry.y = area.y
         geometry.height = area.height / (#cls - 1)
         geometry.width = area.width
 
-        local fidx
-        for k, c in ipairs(cls) do
-            if c == focus then
-                fidx = k
-                break
+        -- We don't know what the focus window index. Try to find it.
+        if not fidx then
+            for k, c in ipairs(cls) do
+                if c == focus then
+                    fidx = k
+                    break
+                end
             end
         end