diff --git a/internal/driver/ui.go b/internal/driver/ui.go
index d18d7aacc..aadb43da1 100644
--- a/internal/driver/ui.go
+++ b/internal/driver/ui.go
@@ -17,8 +17,13 @@ package driver
 import (
 	"errors"
 	"image"
+	"time"
 )
 
+// IsPlayground indicates whether the current environment is the Go Playground (play.golang.org) or not.
+// The fixed time is explicitly defined. See "About the Playground" at play.golang.org.
+var IsPlayground = time.Now().UnixNano() == 1257894000000000000
+
 type UIContext interface {
 	SetSize(width, height int, scale float64)
 	Update(afterFrameUpdate func()) error
diff --git a/internal/graphicsdriver/graphicsdriver_playground.go b/internal/graphicsdriver/graphicsdriver_playground.go
index 38a7b9798..6130d8f8f 100644
--- a/internal/graphicsdriver/graphicsdriver_playground.go
+++ b/internal/graphicsdriver/graphicsdriver_playground.go
@@ -27,7 +27,7 @@ import (
 )
 
 func Get() driver.Graphics {
-	if !isPlayground {
+	if !driver.IsPlayground {
 		panic("ebiten: a graphics driver is not implemented on this environment")
 	}
 	// TODO: Implement this
diff --git a/internal/uidriver/uidriver_playground.go b/internal/uidriver/uidriver_playground.go
index d56110fa9..07300655a 100644
--- a/internal/uidriver/uidriver_playground.go
+++ b/internal/uidriver/uidriver_playground.go
@@ -27,7 +27,7 @@ import (
 )
 
 func Get() driver.UI {
-	if !isPlayground {
+	if !driver.IsPlayground {
 		panic("ebiten: a UI driver is not implemented on this environment")
 	}
 	// TODO: Implement this
diff --git a/run.go b/run.go
index 2db3df130..bbb5e7fd0 100644
--- a/run.go
+++ b/run.go
@@ -17,7 +17,6 @@ package ebiten
 import (
 	"image"
 	"sync/atomic"
-	"time"
 
 	"github.com/hajimehoshi/ebiten/internal/clock"
 	"github.com/hajimehoshi/ebiten/internal/driver"
@@ -28,10 +27,6 @@ import (
 
 var _ = __EBITEN_REQUIRES_GO_VERSION_1_12_OR_LATER__
 
-// isPlayground indicates whether the current environment is the Go Playground (play.golang.org) or not.
-// The fixed time is explicitly defined. See "About the Playground" at play.golang.org.
-var isPlayground = time.Now().UnixNano() == 1257894000000000000
-
 // TPS represents a default ticks per second, that represents how many times game updating happens in a second.
 const DefaultTPS = 60