diff --git a/core/wasm_shims/interp_base_probe_main.cc b/core/wasm_shims/interp_base_probe_main.cc
index 876f77f..9c02a82 100644
--- a/core/wasm_shims/interp_base_probe_main.cc
+++ b/core/wasm_shims/interp_base_probe_main.cc
@@ -24,6 +24,15 @@ int main() {
         return 6;
     }
 
-    InterpBase *interp = interp_from_shlib("nonexistent-interpreter.so");
-    return interp == nullptr ? 0 : 1;
+    // LinuxCNC src/emc/rs274ngc/interp_base.cc uses absolute interpreter
+    // paths directly before calling dlopen().
+    if (interp_from_shlib("/tmp/cnc_sim_missing_absolute_interpreter.so") != nullptr) {
+        return 7;
+    }
+    // Relative interpreter names are resolved through EMC2_HOME/lib/linuxcnc
+    // before the same unavailable dynamic-loading edge is reached.
+    if (interp_from_shlib("nonexistent-interpreter.so") != nullptr) {
+        return 8;
+    }
+    return 0;
 }