diff --git a/infinitecraft/game.go b/infinitecraft/game.go
index 3cbb883..7e55fa5 100644
--- a/infinitecraft/game.go
+++ b/infinitecraft/game.go
@@ -1,10 +1,10 @@
 package infinitecraft
 
 type Game struct {
-	Name      string `json:"name"`
-	Version   string `json:"version"`
-	Created   int64  `json:"created"`
-	Updated   int64  `json:"updated"`
-	Instances []any  `json:"instances" db:"-"`
-	Items     []Item `json:"items" db:"-"`
+	Name      string     `json:"name"`
+	Version   string     `json:"version"`
+	Created   int64      `json:"created"`
+	Updated   int64      `json:"updated"`
+	Instances []Instance `json:"instances" db:"-"`
+	Items     []Item     `json:"items" db:"-"`
 }
diff --git a/infinitecraft/instance.go b/infinitecraft/instance.go
new file mode 100644
index 0000000..c9cb29e
--- /dev/null
+++ b/infinitecraft/instance.go
@@ -0,0 +1,7 @@
+package infinitecraft
+
+type Instance struct {
+	ItemID int32  `json:"itemId"`
+	X      uint16 `json:"x"`
+	Y      uint16 `json:"y"`
+}
diff --git a/infinitecraft/write.go b/infinitecraft/write.go
index 07013d0..8f8e91f 100644
--- a/infinitecraft/write.go
+++ b/infinitecraft/write.go
@@ -26,7 +26,7 @@ func (m *Merger) Write(ctx context.Context, g Game) (out string, err error) {
 	gz.Comment = "merge by ic-merge"
 
 	if g.Instances == nil {
-		g.Instances = make([]any, 0)
+		g.Instances = make([]Instance, 0)
 	}
 
 	enc := json.NewEncoder(gz)