diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e3c466..5091e71 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Add new parameter `cache-directories` that is propagated to `Swatinem/rust-cache` (#44 by @pranc1ngpegasus)
 * Add new parameter `cache-key` that is propagated to `Swatinem/rust-cache` as `key` (#41 by @iainlane)
+* Make rustup toolchain installation more robust in light of planned changes https://github.com/rust-lang/rustup/issues/3635 and https://github.com/rust-lang/rustup/pull/3985
 
 ## [1.9.0] - 2024-06-08
 
diff --git a/action.yml b/action.yml
index d842f6e..f6929f3 100644
--- a/action.yml
+++ b/action.yml
@@ -137,8 +137,10 @@ runs:
         if [[ -z "$toolchain" && ( -f "rust-toolchain" || -f "rust-toolchain.toml" ) ]]
         then
           # Install the toolchain as specified in the file
-          # Might break at some point: https://github.com/rust-lang/rustup/issues/1397
-          rustup show
+          # rustup show is the old way that implicitly installed a toolchain
+          # rustup toolchain install is the new explicit way
+          # https://github.com/rust-lang/rustup/issues/3635#issuecomment-2343511297
+          rustup show active-toolchain || rustup toolchain install
           if [[ -n $components ]]; then
             rustup component add ${components//,/ }
           fi