diff --git a/Cargo.toml b/Cargo.toml
index 21d85bc..6b97b68 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,5 +24,5 @@ futures-core = { version = "0.3", optional = true }
 pin-project-lite = { version = "0.2", optional = true }
 
 # Optional dependencies required for the `serde` feature.
-serde = { version = "1.0", features = ["derive"], optional = true }
-serde_json = { version = "1.0", optional = true }
+serde = { version = "1", features = ["derive"], optional = true }
+serde_json = { version = "1", optional = true }