diff --git a/image-recipe/build-auto-installer-iso.sh b/image-recipe/build-auto-installer-iso.sh
index a56124ca..b23bf633 100755
--- a/image-recipe/build-auto-installer-iso.sh
+++ b/image-recipe/build-auto-installer-iso.sh
@@ -260,10 +260,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \\
 RUN cargo install --locked cargo-deb
 RUN git clone --depth 1 https://github.com/jmcorgan/fips.git /src/fips
 WORKDIR /src/fips
-# fips-gateway is in a separate workspace crate; plain --bins on the
-# root only builds root's bins. --workspace pulls every member crate's
-# bin target so cargo deb finds them all.
-RUN cargo build --release --workspace --bins
+# fips-gateway is gated behind the `gateway` Cargo feature (depends on
+# `rustables`). Without the feature, cargo doesn't build it, and
+# cargo deb --no-build panics hunting for target/release/fips-gateway.
+# Inspected upstream Cargo.toml 2026-04-19 — features.gateway = ["dep:rustables"].
+RUN cargo build --release --features gateway
 RUN cargo deb --no-build
 RUN cp target/debian/fips_*_amd64.deb /tmp/fips.deb