diff --git a/Makefile b/Makefile
index 39d4cb4..f3fb96f 100644
--- a/Makefile
+++ b/Makefile
@@ -9,4 +9,4 @@ check-format:
 	dhall type --file package-set.dhall;
 	@echo checked dhall files are well-typed.
 ci: check-format
-	vessel verify --version 0.9.8
+	vessel verify --version 0.10.0
diff --git a/index/base.dhall b/index/base.dhall
index 2399065..6ab5e14 100644
--- a/index/base.dhall
+++ b/index/base.dhall
@@ -5,6 +5,6 @@
 , authors = [ "DFINITY Languages Team" ]
 , owners = [ "dfinity" ]
 , repo = "https://github.com/dfinity/motoko-base.git"
-, version = "9ea06b464645fbef47e0d21288613b0f9ba2f1cd"
+, version = "a15ca7cd26335505e103288654f480a44463d844"
 , dependencies = [] : List Text
 }