diff --git a/.cargo/config.toml b/.cargo/config.toml
index 334b3e8f5b3201c3e970028a82bc38a3e5f35b57..4b1b35d413d5d17cf970c8cd087906b188d0f1ae 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -1,4 +1,5 @@
 [unstable]
+# Keep in sync with CI!
 build-std = ["core", "alloc"]
 build-std-features = ["compiler-builtins-mem"]
 
diff --git a/.github/workflows/x86.yml b/.github/workflows/x86.yml
index 554fd66f675a851ff698befd2bb64d6601f0b182..04b3a29ccacb487b689a5531d973646b8a6f2d72 100644
--- a/.github/workflows/x86.yml
+++ b/.github/workflows/x86.yml
@@ -39,7 +39,7 @@ jobs:
         run: rustup show
       - name: Build minimal kernel
         working-directory: libhermit-rs
-        run: cargo build --no-default-features
+        run: cargo build --no-default-features -Z build-std=core,alloc
       - name: Build dev profile
         run: cargo build
       - name: Unittests on host (ubuntu)
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index fe707619c244aab1d48825cf02cf9af69fa7ea75..37093c294d8d1dff8f2e12aa14a1c3deb21e269a 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,5 +1,5 @@
 [toolchain]
-channel = "nightly-2021-09-29"
+channel = "nightly-2021-10-20"
 components = [
     "rust-src",
     "llvm-tools-preview",