diff --git a/Cargo.toml b/Cargo.toml
index af45ec9..e3a2988 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,7 +39,7 @@ log = "0.4.1"
 fnv = "1.0.5"
 slab = "0.4.0"
 string = "0.1"
-indexmap = "0.4"
+indexmap = "1.0"
 
 [dev-dependencies]
 tokio-timer = "0.1"