diff --git a/docker/kernel-builder/build.sh b/docker/kernel-builder/build.sh
index 8ee75b0..ea175c0 100644
--- a/docker/kernel-builder/build.sh
+++ b/docker/kernel-builder/build.sh
@@ -34,4 +34,46 @@ make headers_install INSTALL_HDR_PATH="$HDR/usr"
 export srctree=/src SRCARCH=x86
 CC="${CROSS_COMPILE}gcc" HOSTCC=gcc MAKE=make /src/scripts/package/install-extmod-build "$HDR/lib/modules/$KVER/build"
 
+# ---- NXP IW620 mwifiex driver (the PS5's onboard wifi) ----
+# Build the out-of-tree moal+mlan modules against the kernel we just built
+# and stage them into /out/staging so they get bundled in linux-ps5.{deb,rpm,
+# pkg.tar.zst}. Without this, users get no wifi until they manually run
+# ps5-linux-mwifiex/install.sh on the target (which needs gcc + headers).
+echo "=== Building NXP IW620 mwifiex driver ==="
+MWIFIEX_REPO="${MWIFIEX_REPO:-https://github.com/ps5-linux/ps5-linux-mwifiex.git}"
+MWIFIEX_REF="${MWIFIEX_REF:-main}"
+MWIFIEX_NXP_REPO=https://github.com/nxp-imx/mwifiex.git
+MWIFIEX_NXP_REF=lf-6.18.2_1.0.0
+
+PS5_MW=/tmp/ps5-linux-mwifiex
+NXP_MW=/tmp/nxp-mwifiex
+rm -rf "$PS5_MW" "$NXP_MW"
+git clone "$MWIFIEX_REPO" "$PS5_MW"
+git -C "$PS5_MW" checkout "$MWIFIEX_REF" 2>/dev/null || true
+git clone --depth 1 --branch "$MWIFIEX_NXP_REF" "$MWIFIEX_NXP_REPO" "$NXP_MW"
+git -C "$NXP_MW" apply "$PS5_MW/ps5-iw620.patch"
+
+# Build against the kernel source we just built (out-of-tree build needs
+# the in-tree build dir, not just headers; same as install-extmod-build).
+make -C "$NXP_MW" CONFIG_OBJTOOL= KERNELDIR=/src ARCH=x86 -j"$(nproc)"
+[ -f "$NXP_MW/mlan.ko" ] && [ -f "$NXP_MW/moal.ko" ] \
+    || { echo "ERROR: mwifiex build did not produce mlan.ko/moal.ko"; exit 1; }
+
+EXTRA_DIR="/out/staging/lib/modules/$KVER/extra/ps5-iw620"
+mkdir -p "$EXTRA_DIR"
+install -m 0644 "$NXP_MW/mlan.ko" "$EXTRA_DIR/mlan.ko"
+install -m 0644 "$NXP_MW/moal.ko" "$EXTRA_DIR/moal.ko"
+
+# Modprobe + modules-load.d so the driver auto-loads at boot.
+mkdir -p /out/staging/etc/modprobe.d /out/staging/etc/modules-load.d
+echo moal > /out/staging/etc/modules-load.d/moal
+cat > /out/staging/etc/modprobe.d/moal.conf <<'MPCONF'
+# PS5 IW620 mwifiex (NXP moal/mlan, built out-of-tree by kernel-builder).
+softdep moal pre: cfg80211 mlan
+options moal fw_name=nxp/pcieuartiw620_combo_v1.bin pcie_int_mode=1 drv_mode=1 cfg80211_wext=4 sta_name=mlan ext_scan=1 auto_fw_reload=0 wifi_reset_config=0 sched_scan=0 ps_mode=2 auto_ds=2 amsdu_disable=1
+MPCONF
+
+# Rebuild module index so modprobe moal works without depmod -a post-install.
+depmod -b /out/staging "$KVER"
+
 echo "=== Build artifacts staged in /out/staging ==="