diff --git a/crates/base_db/Cargo.toml b/crates/base_db/Cargo.toml
index 15ada0f34a..de88617464 100644
--- a/crates/base_db/Cargo.toml
+++ b/crates/base_db/Cargo.toml
@@ -3,7 +3,7 @@ name = "base_db"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/cfg/Cargo.toml b/crates/cfg/Cargo.toml
index f86199c8c3..6d4ff45b18 100644
--- a/crates/cfg/Cargo.toml
+++ b/crates/cfg/Cargo.toml
@@ -3,7 +3,7 @@ name = "cfg"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/flycheck/Cargo.toml b/crates/flycheck/Cargo.toml
index 83624b494e..2b95ded2ac 100644
--- a/crates/flycheck/Cargo.toml
+++ b/crates/flycheck/Cargo.toml
@@ -3,7 +3,7 @@ name = "flycheck"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/hir/Cargo.toml b/crates/hir/Cargo.toml
index 43059bb8cc..c80605c16c 100644
--- a/crates/hir/Cargo.toml
+++ b/crates/hir/Cargo.toml
@@ -3,7 +3,7 @@ name = "hir"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/hir_def/Cargo.toml b/crates/hir_def/Cargo.toml
index 8f989bc0ae..bdfad530b0 100644
--- a/crates/hir_def/Cargo.toml
+++ b/crates/hir_def/Cargo.toml
@@ -3,7 +3,7 @@ name = "hir_def"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 03fe46e267..3bf7a33030 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -1,12 +1,6 @@
 //! A higher level attributes based on TokenTree, with also some shortcuts.
 
-use std::{
-    convert::{TryFrom, TryInto},
-    fmt,
-    hash::Hash,
-    ops,
-    sync::Arc,
-};
+use std::{fmt, hash::Hash, ops, sync::Arc};
 
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
diff --git a/crates/hir_expand/Cargo.toml b/crates/hir_expand/Cargo.toml
index b73a0c420f..520c2208d6 100644
--- a/crates/hir_expand/Cargo.toml
+++ b/crates/hir_expand/Cargo.toml
@@ -3,7 +3,7 @@ name = "hir_expand"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index d05c3ee5c3..fcb2e1d2e9 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -3,7 +3,7 @@ name = "hir_ty"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide/Cargo.toml b/crates/ide/Cargo.toml
index bccadacdb2..62043b82ad 100644
--- a/crates/ide/Cargo.toml
+++ b/crates/ide/Cargo.toml
@@ -3,7 +3,7 @@ name = "ide"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 3b7a2c8b5f..c184b014ba 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -2,8 +2,6 @@
 
 mod intra_doc_links;
 
-use std::convert::{TryFrom, TryInto};
-
 use either::Either;
 use pulldown_cmark::{BrokenLink, CowStr, Event, InlineStr, LinkType, Options, Parser, Tag};
 use pulldown_cmark_to_cmark::{cmark_with_options, Options as CmarkOptions};
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
index 4851f9aee0..54c0b5e704 100644
--- a/crates/ide/src/join_lines.rs
+++ b/crates/ide/src/join_lines.rs
@@ -1,5 +1,3 @@
-use std::convert::TryFrom;
-
 use ide_assists::utils::extract_trivial_expression;
 use ide_db::helpers::node_ext::expr_as_name_ref;
 use itertools::Itertools;
diff --git a/crates/ide_assists/Cargo.toml b/crates/ide_assists/Cargo.toml
index 629aadb5b1..f9f9b3936f 100644
--- a/crates/ide_assists/Cargo.toml
+++ b/crates/ide_assists/Cargo.toml
@@ -3,7 +3,7 @@ name = "ide_assists"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide_completion/Cargo.toml b/crates/ide_completion/Cargo.toml
index 5b2f0b35f9..27abf77938 100644
--- a/crates/ide_completion/Cargo.toml
+++ b/crates/ide_completion/Cargo.toml
@@ -3,7 +3,7 @@ name = "ide_completion"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide_db/Cargo.toml b/crates/ide_db/Cargo.toml
index 54179b6fba..754b6f1a09 100644
--- a/crates/ide_db/Cargo.toml
+++ b/crates/ide_db/Cargo.toml
@@ -3,7 +3,7 @@ name = "ide_db"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide_diagnostics/Cargo.toml b/crates/ide_diagnostics/Cargo.toml
index 7e36b1a3bd..adb3c2f72f 100644
--- a/crates/ide_diagnostics/Cargo.toml
+++ b/crates/ide_diagnostics/Cargo.toml
@@ -3,7 +3,7 @@ name = "ide_diagnostics"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/ide_ssr/Cargo.toml b/crates/ide_ssr/Cargo.toml
index 275f923f2b..ad6e37f50a 100644
--- a/crates/ide_ssr/Cargo.toml
+++ b/crates/ide_ssr/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.0"
 description = "Structural search and replace of Rust code"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-analyzer/rust-analyzer"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/limit/Cargo.toml b/crates/limit/Cargo.toml
index cb3ccbd73c..0bee06b0c8 100644
--- a/crates/limit/Cargo.toml
+++ b/crates/limit/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
 authors = ["rust-analyzer developers"]
-edition = "2018"
+edition = "2021"
 
 [features]
 tracking = []
diff --git a/crates/mbe/Cargo.toml b/crates/mbe/Cargo.toml
index 5378516e70..3cb06f3d8a 100644
--- a/crates/mbe/Cargo.toml
+++ b/crates/mbe/Cargo.toml
@@ -3,7 +3,7 @@ name = "mbe"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/parser/Cargo.toml b/crates/parser/Cargo.toml
index 39c1904590..d74c903686 100644
--- a/crates/parser/Cargo.toml
+++ b/crates/parser/Cargo.toml
@@ -3,7 +3,7 @@ name = "parser"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/paths/Cargo.toml b/crates/paths/Cargo.toml
index cc062ebb7c..446b8a5d68 100644
--- a/crates/paths/Cargo.toml
+++ b/crates/paths/Cargo.toml
@@ -3,7 +3,7 @@ name = "paths"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/paths/src/lib.rs b/crates/paths/src/lib.rs
index 41731c8d27..b4beb40e74 100644
--- a/crates/paths/src/lib.rs
+++ b/crates/paths/src/lib.rs
@@ -2,7 +2,6 @@
 //! relative paths.
 use std::{
     borrow::Borrow,
-    convert::{TryFrom, TryInto},
     ffi::OsStr,
     ops,
     path::{Component, Path, PathBuf},
diff --git a/crates/proc_macro_api/Cargo.toml b/crates/proc_macro_api/Cargo.toml
index 5b1655b918..75ab9c13a4 100644
--- a/crates/proc_macro_api/Cargo.toml
+++ b/crates/proc_macro_api/Cargo.toml
@@ -3,7 +3,7 @@ name = "proc_macro_api"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/proc_macro_srv/Cargo.toml b/crates/proc_macro_srv/Cargo.toml
index 6048c5e6cc..fab9cceb70 100644
--- a/crates/proc_macro_srv/Cargo.toml
+++ b/crates/proc_macro_srv/Cargo.toml
@@ -3,7 +3,7 @@ name = "proc_macro_srv"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/proc_macro_test/Cargo.toml b/crates/proc_macro_test/Cargo.toml
index 8c3eeefc0b..547a95d6e0 100644
--- a/crates/proc_macro_test/Cargo.toml
+++ b/crates/proc_macro_test/Cargo.toml
@@ -2,7 +2,7 @@
 name = "proc_macro_test"
 version = "0.0.0"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [lib]
diff --git a/crates/proc_macro_test/imp/Cargo.toml b/crates/proc_macro_test/imp/Cargo.toml
index b718db968d..27ea2d9a8b 100644
--- a/crates/proc_macro_test/imp/Cargo.toml
+++ b/crates/proc_macro_test/imp/Cargo.toml
@@ -2,7 +2,7 @@
 name = "proc_macro_test_impl"
 version = "0.0.0"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 publish = false
 
 [lib]
diff --git a/crates/profile/Cargo.toml b/crates/profile/Cargo.toml
index 6014ef3e1c..05b1c0b392 100644
--- a/crates/profile/Cargo.toml
+++ b/crates/profile/Cargo.toml
@@ -3,7 +3,7 @@ name = "profile"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/project_model/Cargo.toml b/crates/project_model/Cargo.toml
index 2cba46a59b..7c930f6896 100644
--- a/crates/project_model/Cargo.toml
+++ b/crates/project_model/Cargo.toml
@@ -3,7 +3,7 @@ name = "project_model"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/project_model/src/cargo_workspace.rs b/crates/project_model/src/cargo_workspace.rs
index 13ff20c8c6..24b7398ee6 100644
--- a/crates/project_model/src/cargo_workspace.rs
+++ b/crates/project_model/src/cargo_workspace.rs
@@ -1,6 +1,5 @@
 //! See [`CargoWorkspace`].
 
-use std::convert::{TryFrom, TryInto};
 use std::iter;
 use std::path::PathBuf;
 use std::{ops, process::Command};
diff --git a/crates/project_model/src/lib.rs b/crates/project_model/src/lib.rs
index e1bc5fe86b..1caf6b59bc 100644
--- a/crates/project_model/src/lib.rs
+++ b/crates/project_model/src/lib.rs
@@ -28,7 +28,6 @@ mod build_scripts;
 mod tests;
 
 use std::{
-    convert::{TryFrom, TryInto},
     fs::{self, read_dir, ReadDir},
     io,
     process::Command,
diff --git a/crates/project_model/src/manifest_path.rs b/crates/project_model/src/manifest_path.rs
index 5683bf13b1..4910fd3d11 100644
--- a/crates/project_model/src/manifest_path.rs
+++ b/crates/project_model/src/manifest_path.rs
@@ -1,5 +1,5 @@
 //! See [`ManifestPath`].
-use std::{convert::TryFrom, ops, path::Path};
+use std::{ops, path::Path};
 
 use paths::{AbsPath, AbsPathBuf};
 
diff --git a/crates/project_model/src/sysroot.rs b/crates/project_model/src/sysroot.rs
index a7a7cb6da0..415bc4c9b7 100644
--- a/crates/project_model/src/sysroot.rs
+++ b/crates/project_model/src/sysroot.rs
@@ -4,7 +4,7 @@
 //! but we can't process `.rlib` and need source code instead. The source code
 //! is typically installed with `rustup component add rust-src` command.
 
-use std::{convert::TryFrom, env, fs, iter, ops, path::PathBuf, process::Command};
+use std::{env, fs, iter, ops, path::PathBuf, process::Command};
 
 use anyhow::{format_err, Result};
 use la_arena::{Arena, Idx};
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index 339fdfcc9b..54e3bae17b 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -2,7 +2,7 @@
 //! metadata` or `rust-project.json`) into representation stored in the salsa
 //! database -- `CrateGraph`.
 
-use std::{collections::VecDeque, convert::TryFrom, fmt, fs, process::Command};
+use std::{collections::VecDeque, fmt, fs, process::Command};
 
 use anyhow::{format_err, Context, Result};
 use base_db::{
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 2d3d00fd98..5d3aac42e3 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -7,7 +7,7 @@ description = "A language server for the Rust programming language"
 documentation = "https://rust-analyzer.github.io/manual.html"
 license = "MIT OR Apache-2.0"
 autobins = false
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index 74c041020b..ef90610f85 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -4,7 +4,7 @@
 mod logger;
 mod rustc_wrapper;
 
-use std::{convert::TryFrom, env, fs, path::Path, process};
+use std::{env, fs, path::Path, process};
 
 use lsp_server::Connection;
 use project_model::ProjectManifest;
diff --git a/crates/rust-analyzer/src/from_proto.rs b/crates/rust-analyzer/src/from_proto.rs
index a95836edda..4cbf2b1124 100644
--- a/crates/rust-analyzer/src/from_proto.rs
+++ b/crates/rust-analyzer/src/from_proto.rs
@@ -1,6 +1,4 @@
 //! Conversion lsp_types types to rust-analyzer specific ones.
-use std::convert::TryFrom;
-
 use ide::{Annotation, AnnotationKind, AssistKind, LineCol, LineColUtf16};
 use ide_db::base_db::{FileId, FilePosition, FileRange};
 use syntax::{TextRange, TextSize};
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index ab656d4789..ee409c3da8 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -3,7 +3,6 @@
 //! `ide` crate.
 
 use std::{
-    convert::TryFrom,
     io::Write as _,
     process::{self, Stdio},
 };
diff --git a/crates/rust-analyzer/src/integrated_benchmarks.rs b/crates/rust-analyzer/src/integrated_benchmarks.rs
index b10eb3d6e9..c745af3da6 100644
--- a/crates/rust-analyzer/src/integrated_benchmarks.rs
+++ b/crates/rust-analyzer/src/integrated_benchmarks.rs
@@ -10,7 +10,7 @@
 //! in release mode in VS Code. There's however "Rust Analyzer: Copy Run Command Line"
 //! which you can use to paste the command in terminal and add `--release` manually.
 
-use std::{convert::TryFrom, sync::Arc};
+use std::sync::Arc;
 
 use ide::{Change, CompletionConfig, FilePosition, TextSize};
 use ide_db::helpers::{
diff --git a/crates/rust-analyzer/tests/slow-tests/main.rs b/crates/rust-analyzer/tests/slow-tests/main.rs
index 9eb8ad1b72..073721adc9 100644
--- a/crates/rust-analyzer/tests/slow-tests/main.rs
+++ b/crates/rust-analyzer/tests/slow-tests/main.rs
@@ -350,7 +350,7 @@ fn test_format_document_2018() {
 [package]
 name = "foo"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 
 //- /src/lib.rs
 mod bar;
@@ -799,7 +799,7 @@ fn resolve_proc_macro() {
 [package]
 name = "foo"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 [dependencies]
 bar = {path = "../bar"}
 
@@ -818,7 +818,7 @@ fn main() {
 [package]
 name = "bar"
 version = "0.0.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 proc-macro = true
diff --git a/crates/sourcegen/Cargo.toml b/crates/sourcegen/Cargo.toml
index e7d618b8c7..20954dfb47 100644
--- a/crates/sourcegen/Cargo.toml
+++ b/crates/sourcegen/Cargo.toml
@@ -3,7 +3,7 @@ name = "sourcegen"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/stdx/Cargo.toml b/crates/stdx/Cargo.toml
index f6154f1b54..e37ecc8241 100644
--- a/crates/stdx/Cargo.toml
+++ b/crates/stdx/Cargo.toml
@@ -3,7 +3,7 @@ name = "stdx"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index d5fc7893cf..377e8aeab2 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -4,7 +4,7 @@ version = "0.0.0"
 description = "Comment and whitespace preserving parser for the Rust language"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-analyzer/rust-analyzer"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/syntax/fuzz/Cargo.toml b/crates/syntax/fuzz/Cargo.toml
index f01593fd99..37394c5ba8 100644
--- a/crates/syntax/fuzz/Cargo.toml
+++ b/crates/syntax/fuzz/Cargo.toml
@@ -3,7 +3,7 @@
 name = "syntax-fuzz"
 version = "0.0.1"
 publish = false
-edition = "2018"
+edition = "2021"
 
 [package.metadata]
 cargo-fuzz = true
diff --git a/crates/syntax/src/ast/token_ext.rs b/crates/syntax/src/ast/token_ext.rs
index 2f8312d5d1..1fb7f158f2 100644
--- a/crates/syntax/src/ast/token_ext.rs
+++ b/crates/syntax/src/ast/token_ext.rs
@@ -1,9 +1,6 @@
 //! There are many AstNodes, but only a few tokens, so we hand-write them here.
 
-use std::{
-    borrow::Cow,
-    convert::{TryFrom, TryInto},
-};
+use std::borrow::Cow;
 
 use rustc_lexer::unescape::{unescape_literal, Mode};
 
diff --git a/crates/syntax/src/validation.rs b/crates/syntax/src/validation.rs
index 521ffce20e..af5e173900 100644
--- a/crates/syntax/src/validation.rs
+++ b/crates/syntax/src/validation.rs
@@ -4,8 +4,6 @@
 
 mod block;
 
-use std::convert::TryFrom;
-
 use rowan::Direction;
 use rustc_lexer::unescape::{
     self, unescape_byte, unescape_byte_literal, unescape_char, unescape_literal, Mode,
diff --git a/crates/test_utils/Cargo.toml b/crates/test_utils/Cargo.toml
index b2ea1065a0..199155c0df 100644
--- a/crates/test_utils/Cargo.toml
+++ b/crates/test_utils/Cargo.toml
@@ -3,7 +3,7 @@ name = "test_utils"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 146e4f0c30..871ff20a9b 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -12,7 +12,6 @@ mod assert_linear;
 
 use std::{
     collections::BTreeMap,
-    convert::{TryFrom, TryInto},
     env, fs,
     path::{Path, PathBuf},
 };
diff --git a/crates/text_edit/Cargo.toml b/crates/text_edit/Cargo.toml
index b86f2dcfcf..cce0d85c52 100644
--- a/crates/text_edit/Cargo.toml
+++ b/crates/text_edit/Cargo.toml
@@ -3,7 +3,7 @@ name = "text_edit"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/toolchain/Cargo.toml b/crates/toolchain/Cargo.toml
index 8d8022eb47..76f61519b7 100644
--- a/crates/toolchain/Cargo.toml
+++ b/crates/toolchain/Cargo.toml
@@ -3,7 +3,7 @@ name = "toolchain"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/tt/Cargo.toml b/crates/tt/Cargo.toml
index e24a9998c7..5b3d8c4ee4 100644
--- a/crates/tt/Cargo.toml
+++ b/crates/tt/Cargo.toml
@@ -3,7 +3,7 @@ name = "tt"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/vfs-notify/Cargo.toml b/crates/vfs-notify/Cargo.toml
index 2b578ff9a4..4f24c595eb 100644
--- a/crates/vfs-notify/Cargo.toml
+++ b/crates/vfs-notify/Cargo.toml
@@ -3,7 +3,7 @@ name = "vfs-notify"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/vfs-notify/src/lib.rs b/crates/vfs-notify/src/lib.rs
index a2a53cdc9e..b5783cef21 100644
--- a/crates/vfs-notify/src/lib.rs
+++ b/crates/vfs-notify/src/lib.rs
@@ -6,7 +6,7 @@
 //!
 //! Hopefully, one day a reliable file watching/walking crate appears on
 //! crates.io, and we can reduce this to trivial glue code.
-use std::{convert::TryFrom, fs};
+use std::fs;
 
 use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
diff --git a/crates/vfs/Cargo.toml b/crates/vfs/Cargo.toml
index 06c77bcc41..ca0def4f34 100644
--- a/crates/vfs/Cargo.toml
+++ b/crates/vfs/Cargo.toml
@@ -3,7 +3,7 @@ name = "vfs"
 version = "0.0.0"
 description = "TBD"
 license = "MIT OR Apache-2.0"
-edition = "2018"
+edition = "2021"
 
 [lib]
 doctest = false
diff --git a/crates/vfs/src/vfs_path.rs b/crates/vfs/src/vfs_path.rs
index c4ecc9bb05..668c7320d4 100644
--- a/crates/vfs/src/vfs_path.rs
+++ b/crates/vfs/src/vfs_path.rs
@@ -267,7 +267,6 @@ mod windows_paths {
     #[cfg(test)]
     fn vfs(str: &str) -> super::VfsPath {
         use super::{AbsPathBuf, VfsPath};
-        use std::convert::TryFrom;
         VfsPath::from(AbsPathBuf::try_from(str).unwrap())
     }
 }
diff --git a/lib/arena/Cargo.toml b/lib/arena/Cargo.toml
index 23f1d9e881..3fc690ff26 100644
--- a/lib/arena/Cargo.toml
+++ b/lib/arena/Cargo.toml
@@ -6,4 +6,4 @@ license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-analyzer/rust-analyzer"
 documentation = "https://docs.rs/la-arena"
 categories = ["data-structures", "memory-management", "rust-patterns"]
-edition = "2018"
+edition = "2021"
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
index 93e075885d..c743cd884d 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-edition = "2018"
+edition = "2021"
 name = "xtask"
 version = "0.1.0"
 publish = false
diff --git a/xtask/src/install.rs b/xtask/src/install.rs
index d026df6c15..412132f60e 100644
--- a/xtask/src/install.rs
+++ b/xtask/src/install.rs
@@ -8,7 +8,7 @@ use xshell::{cmd, pushd};
 use crate::flags;
 
 // Latest stable, feel free to send a PR if this lags behind.
-const REQUIRED_RUST_VERSION: u32 = 55;
+const REQUIRED_RUST_VERSION: u32 = 56;
 
 impl flags::Install {
     pub(crate) fn run(self) -> Result<()> {