diff --git a/test-linuxcnc-wasm-cmake-safe-probe.sh b/test-linuxcnc-wasm-cmake-safe-probe.sh
index 12e56f3..68bbb09 100755
--- a/test-linuxcnc-wasm-cmake-safe-probe.sh
+++ b/test-linuxcnc-wasm-cmake-safe-probe.sh
@@ -437,6 +437,8 @@ grep -F 'build_jobs=${CNC_SIM_BUILD_JOBS:-8}' test-linuxcnc-wasm-interp-find-lin
 grep -F 'CNC_SIM_BUILD_JOBS must be a positive integer: $build_jobs' test-linuxcnc-wasm-interp-find-link.sh >/dev/null
 grep -F 'command -v ccache >/dev/null 2>&1' test-linuxcnc-wasm-interp-find-link.sh >/dev/null
 grep -F 'check-linuxcnc-inputs-cached.sh --cache-dir "$preflight_cache_dir" --root-only' test-linuxcnc-wasm-interp-find-link.sh >/dev/null
+grep -F 'LinuxCNC source basis: src/emc/rs274ngc/interp_find.cc implements' core/wasm_shims/interp_find_probe_main.cc >/dev/null
+grep -F 'LinuxCNC source basis: src/emc/rs274ngc/rs274ngc_interp.hh declares' core/wasm_shims/interp_find_probe_stubs.cc >/dev/null
 grep -F 'signature="$build_dir/interp-find.signature"' test-linuxcnc-wasm-interp-find-link.sh >/dev/null
 grep -F "printf 'BUILD_RULE_VERSION=1\n'" test-linuxcnc-wasm-interp-find-link.sh >/dev/null
 grep -F 'make --output-sync=target -j"$build_jobs" -f "$makefile" >/dev/null' test-linuxcnc-wasm-interp-find-link.sh >/dev/null