diff --git a/Cargo.lock b/Cargo.lock
index 0b708105..a7b341f3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -614,7 +614,7 @@ dependencies = [
 
 [[package]]
 name = "tskit"
-version = "0.15.0-alpha.3"
+version = "0.15.0-alpha.4"
 dependencies = [
  "bincode",
  "bindgen",