diff --git a/src/spectator/config_builder.cr b/src/spectator/config_builder.cr
index 42544eb..d65ffc1 100644
--- a/src/spectator/config_builder.cr
+++ b/src/spectator/config_builder.cr
@@ -12,7 +12,7 @@ module Spectator
     protected getter random = Random::DEFAULT
 
     def initialize
-      @seed = seed = @random.rand(UInt64)
+      @seed = seed = @random.rand(UInt16).to_u64
       @random.new_seed(seed)
     end