diff --git a/lib/gears/timer.lua b/lib/gears/timer.lua
index 839f3400..b1a9644a 100644
--- a/lib/gears/timer.lua
+++ b/lib/gears/timer.lua
@@ -61,6 +61,7 @@ local glib = require("lgi").GLib
 local object = require("gears.object")
 local protected_call = require("gears.protected_call")
 local gdebug = require("gears.debug")
+local gmath = require("gears.math")
 
 --- Timer objects. This type of object is useful when triggering events repeatedly.
 --
@@ -96,7 +97,8 @@ function timer:start()
         gdebug.print_error(traceback("timer already started"))
         return
     end
-    self.data.source_id = glib.timeout_add(glib.PRIORITY_DEFAULT, self.data.timeout * 1000, function()
+    local timeout_ms = gmath.round(self.data.timeout * 1000)
+    self.data.source_id = glib.timeout_add(glib.PRIORITY_DEFAULT, timeout_ms, function()
         protected_call(self.emit_signal, self, "timeout")
         return true
     end)
diff --git a/lib/wibox/hierarchy.lua b/lib/wibox/hierarchy.lua
index d0e07d63..3472716d 100644
--- a/lib/wibox/hierarchy.lua
+++ b/lib/wibox/hierarchy.lua
@@ -172,6 +172,10 @@ function hierarchy_update(self, context, widget, width, height, region, matrix_t
     -- Are there any children which were removed? Their area needs a redraw.
     for _, child in ipairs(old_children) do
         local x, y, w, h = matrix.transform_rectangle(child._matrix_to_device, child:get_draw_extents())
+        x = math.floor(x)
+        y = math.floor(y)
+        w = math.ceil(w)
+        h = math.ceil(h)
         region:union_rectangle(cairo.RectangleInt{
             x = x, y = y, width = w, height = h
         })