diff --git a/internal/uidriver/glfw/ui.go b/internal/uidriver/glfw/ui.go
index c782e9cd1..ecd48a317 100644
--- a/internal/uidriver/glfw/ui.go
+++ b/internal/uidriver/glfw/ui.go
@@ -22,7 +22,6 @@ package glfw
 import (
 	"fmt"
 	"image"
-	"math"
 	"os"
 	"runtime"
 	"sync"
@@ -804,8 +803,8 @@ func (u *UserInterface) updateSize() {
 				h = u.fromGLFWPixel(float64(wh))
 			}
 			// On Linux/UNIX, further adjusting is required (#1307).
-			w = math.Ceil(u.toFramebufferPixel(w))
-			h = math.Ceil(u.toFramebufferPixel(h))
+			w = u.toFramebufferPixel(w)
+			h = u.toFramebufferPixel(h)
 			return nil
 		})
 		u.context.Layout(w, h)
diff --git a/internal/uidriver/glfw/ui_unix.go b/internal/uidriver/glfw/ui_unix.go
index a1f2ae514..297f4bea8 100644
--- a/internal/uidriver/glfw/ui_unix.go
+++ b/internal/uidriver/glfw/ui_unix.go
@@ -19,12 +19,14 @@
 package glfw
 
 import (
+	"math"
+
 	"github.com/hajimehoshi/ebiten/internal/glfw"
 )
 
 // fromGLFWMonitorPixel must be called from the main thread.
 func (u *UserInterface) fromGLFWMonitorPixel(x float64) float64 {
-	return x / u.deviceScaleFactor()
+	return math.Ceil(x / u.deviceScaleFactor())
 }
 
 // fromGLFWPixel must be called from the main thread.
@@ -44,7 +46,7 @@ func (u *UserInterface) toGLFWPixel(x float64) float64 {
 // toFramebufferPixel must be called from the main thread.
 func (u *UserInterface) toFramebufferPixel(x float64) float64 {
 	s, _ := currentMonitor(u.window).GetContentScale()
-	return x / u.deviceScaleFactor() * float64(s)
+	return math.Ceil(x * float64(s) / u.deviceScaleFactor())
 }
 
 func (u *UserInterface) adjustWindowPosition(x, y int) (int, int) {