diff --git a/.github/workflows/ml-kem.yml b/.github/workflows/ml-kem.yml
index 035535f..8015ecb 100644
--- a/.github/workflows/ml-kem.yml
+++ b/.github/workflows/ml-kem.yml
@@ -32,10 +32,7 @@ jobs:
           - ${{needs.set-msrv.outputs.msrv}}
           - stable
         target:
-          # XXX(bifurcation) We have a dependency on `sha3`, which has a
-          # transitive `std` dependency by default.  It appears that we can turn
-          # this off via Cargo.
-          # - thumbv7em-none-eabi
+          - thumbv7em-none-eabi
           - wasm32-unknown-unknown
     steps:
       - uses: actions/checkout@v4
diff --git a/ml-kem/Cargo.toml b/ml-kem/Cargo.toml
index da6c1f8..8cba6c2 100644
--- a/ml-kem/Cargo.toml
+++ b/ml-kem/Cargo.toml
@@ -6,7 +6,8 @@ rust-version = "1.74"
 license = "Apache-2.0 OR MIT"
 
 [features]
-default = []
+default = ["std"]
+std = ["sha3/std"]
 deterministic = [] # Expose deterministic generation and encapsulation functions
 
 [dependencies]