diff --git a/Cargo.lock b/Cargo.lock
index 243a326646c38..b45e624db35ea 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1151,12 +1151,13 @@ dependencies = [
 
 [[package]]
 name = "getrandom"
-version = "0.1.8"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34f33de6f0ae7c9cb5e574502a562e2b512799e32abb801cd1e79ad952b62b49"
+checksum = "fc344b02d3868feb131e8b5fe2b9b0a1cc42942679af493061fc13b853243872"
 dependencies = [
  "cfg-if",
  "libc",
+ "wasi",
 ]
 
 [[package]]
@@ -1583,9 +1584,9 @@ checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 
 [[package]]
 name = "libc"
-version = "0.2.61"
+version = "0.2.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c665266eb592905e8503ba3403020f4b8794d26263f412ca33171600eca9a6fa"
+checksum = "34fcd2c08d2f832f376f4173a231990fa5aef4e99fb569867318a227ef4c06ba"
 dependencies = [
  "rustc-std-workspace-core",
 ]
@@ -3248,7 +3249,7 @@ version = "0.0.0"
 dependencies = [
  "graphviz",
  "log",
- "rand 0.6.1",
+ "rand 0.7.0",
  "rustc",
  "rustc_data_structures",
  "rustc_fs_util",
@@ -3864,7 +3865,7 @@ dependencies = [
  "panic_abort",
  "panic_unwind",
  "profiler_builtins",
- "rand 0.6.1",
+ "rand 0.7.0",
  "rustc_asan",
  "rustc_lsan",
  "rustc_msan",
@@ -4686,6 +4687,12 @@ dependencies = [
  "try-lock",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd5442abcac6525a045cc8c795aedb60da7a2e5e89c7bf18a0d5357849bb23c7"
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
diff --git a/src/librustc_incremental/Cargo.toml b/src/librustc_incremental/Cargo.toml
index a931ad3b66e21..659c4c89fe33c 100644
--- a/src/librustc_incremental/Cargo.toml
+++ b/src/librustc_incremental/Cargo.toml
@@ -12,7 +12,7 @@ doctest = false
 [dependencies]
 graphviz = { path = "../libgraphviz" }
 log = "0.4"
-rand = "0.6"
+rand = "0.7"
 rustc = { path = "../librustc" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_serialize = { path = "../libserialize", package = "serialize" }
diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index 157faa0af9bca..fb4a05a39c994 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -38,7 +38,7 @@ features = [
 optional = true
 
 [dev-dependencies]
-rand = "0.6.1"
+rand = "0.7"
 
 [target.x86_64-apple-darwin.dependencies]
 rustc_asan = { path = "../librustc_asan" }
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index 5f76875bd66c4..b14e02a2cb478 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -2144,7 +2144,7 @@ mod tests {
     use crate::sys_common::io::test::{TempDir, tmpdir};
     use crate::thread;
 
-    use rand::{rngs::StdRng, FromEntropy, RngCore};
+    use rand::{rngs::StdRng, RngCore, SeedableRng};
 
     #[cfg(windows)]
     use crate::os::windows::fs::{symlink_dir, symlink_file};
diff --git a/src/libstd/tests/env.rs b/src/libstd/tests/env.rs
index 06fb5533afdd8..f8014cb2ad9af 100644
--- a/src/libstd/tests/env.rs
+++ b/src/libstd/tests/env.rs
@@ -5,7 +5,7 @@ use rand::{thread_rng, Rng};
 use rand::distributions::Alphanumeric;
 
 fn make_rand_name() -> OsString {
-    let mut rng = thread_rng();
+    let rng = thread_rng();
     let n = format!("TEST{}", rng.sample_iter(&Alphanumeric).take(10)
                                  .collect::<String>());
     let n = OsString::from(n);
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index a564b991c404b..b00e8d5b44275 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -172,6 +172,7 @@ const WHITELIST: &[Crate<'_>] = &[
     Crate("vcpkg"),
     Crate("version_check"),
     Crate("void"),
+    Crate("wasi"),
     Crate("winapi"),
     Crate("winapi-build"),
     Crate("winapi-i686-pc-windows-gnu"),