diff --git a/doc/play/solitaire.go b/doc/play/solitaire.go
index 546bc102069..759d5428151 100644
--- a/doc/play/solitaire.go
+++ b/doc/play/solitaire.go
@@ -14,7 +14,7 @@ const N = 11 + 1 // length of a row (+1 for \n)
 // Periods represent illegal fields,
 // ● are pegs, and ○ are holes.
 
-var board = []int(
+var board = []rune(
 	`...........
 ...........
 ....●●●....