diff --git a/Cargo.toml b/Cargo.toml
index ee8451b..56dda40 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,7 @@ readme = "README.md"
 keywords = ["deflate", "gzip", "zlib"]
 categories = ["compression", "no-std"]
 license = "MIT"
-edition = "2018"
+edition = "2021"
 
 [badges]
 coveralls = {repository = "sile/libflate"}
diff --git a/libflate_lz77/Cargo.toml b/libflate_lz77/Cargo.toml
index caa8523..d3e5da5 100644
--- a/libflate_lz77/Cargo.toml
+++ b/libflate_lz77/Cargo.toml
@@ -2,7 +2,7 @@
 name = "libflate_lz77"
 version = "2.0.0"
 authors = ["Takeru Ohta <phjgt308@gmail.com>"]
-edition = "2018"
+edition = "2021"
 description = "LZ77 encoder for libflate crate"
 homepage = "https://github.com/sile/libflate"
 repository = "https://github.com/sile/libflate"