diff --git a/rust-toolchain b/rust-toolchain
deleted file mode 100644
index 2b782427dd..0000000000
--- a/rust-toolchain
+++ /dev/null
@@ -1 +0,0 @@
-nightly-2021-06-15
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000000..4d97fdddba
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,3 @@
+[toolchain]
+channel = "nightly-2021-06-15"
+components = ["rust-src"]