diff --git a/core/wasm_shims/rtapi_compat.cc b/core/wasm_shims/rtapi_compat.cc
index 20cf0c5..e1de0ef 100644
--- a/core/wasm_shims/rtapi_compat.cc
+++ b/core/wasm_shims/rtapi_compat.cc
@@ -1,8 +1,8 @@
 #include <cstdarg>
 #include <cstdio>
 
-// LinuxCNC source basis: src/rtapi/rtai_rtapi.c provides rtapi_snprintf()
-// for RTAPI-compatible formatting call sites.
+// LinuxCNC source basis: src/rtapi/uspace_common.h provides rtapi_snprintf()
+// for userspace RTAPI formatting; src/rtapi/rtapi.h declares the API.
 extern "C" int rtapi_snprintf(char *buf, unsigned long size, const char *fmt, ...) {
     va_list ap;
     va_start(ap, fmt);
diff --git a/test-linuxcnc-wasm-cmake-safe-probe.sh b/test-linuxcnc-wasm-cmake-safe-probe.sh
index ab1edb5..12e56f3 100755
--- a/test-linuxcnc-wasm-cmake-safe-probe.sh
+++ b/test-linuxcnc-wasm-cmake-safe-probe.sh
@@ -1455,7 +1455,7 @@ grep -F 'LinuxCNC source basis: src/libnml/nml/nmlmsg.cc and stat_msg.cc provide
 grep -F 'wasm_shims/nml_status_shim.cc' core/CMakeLists.txt >/dev/null
 grep -F 'LinuxCNC source basis: src/libnml/rcs/rcs_print.cc provides these RCS' core/wasm_shims/rcs_print_shim.cc >/dev/null
 grep -F 'wasm_shims/rcs_print_shim.cc' core/CMakeLists.txt >/dev/null
-grep -F 'LinuxCNC source basis: src/rtapi/rtai_rtapi.c provides rtapi_snprintf()' core/wasm_shims/rtapi_compat.cc >/dev/null
+grep -F 'LinuxCNC source basis: src/rtapi/uspace_common.h provides rtapi_snprintf()' core/wasm_shims/rtapi_compat.cc >/dev/null
 grep -F '$<TARGET_OBJECTS:linuxcnc_rs274_wasm_safe_probe_objects>' core/CMakeLists.txt >/dev/null
 grep -F '$<TARGET_OBJECTS:cnc_sim_objects>' core/CMakeLists.txt >/dev/null
 grep -F 'CNC_SIM_ENABLE_LINUXCNC_RS274_BACKEND' core/CMakeLists.txt >/dev/null