diff --git a/src/c/alloc_2.d b/src/c/alloc_2.d
index fa8bebdc7..f651bdc09 100644
--- a/src/c/alloc_2.d
+++ b/src/c/alloc_2.d
@@ -549,13 +549,9 @@ si_get_finalizer(cl_object o)
 	@(return output)
 }
 
-cl_object
-si_set_finalizer(cl_object o, cl_object finalizer)
+void
+ecl_set_finalizer_unprotected(cl_object o, cl_object finalizer)
 {
-	const cl_env_ptr the_env = ecl_process_env();
-	GC_finalization_proc ofn;
-	void *odata;
-	ecl_disable_interrupts_env(the_env);
 	if (finalizer == Cnil) {
 		GC_register_finalizer_no_order(o, (GC_finalization_proc)0,
 					       0, &ofn, &odata);
@@ -565,6 +561,16 @@ si_set_finalizer(cl_object o, cl_object finalizer)
 		GC_register_finalizer_no_order(o, newfn, finalizer,
 					       &ofn, &odata);
 	}
+}
+
+cl_object
+si_set_finalizer(cl_object o, cl_object finalizer)
+{
+	const cl_env_ptr the_env = ecl_process_env();
+	GC_finalization_proc ofn;
+	void *odata;
+	ecl_disable_interrupts_env(the_env);
+        ecl_set_finalizer_unprotected(o, finalizer);
 	ecl_enable_interrupts_env(the_env);
 	@(return)
 }
diff --git a/src/h/external.h b/src/h/external.h
index a363adbf7..f9700666e 100644
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -657,6 +657,7 @@ extern ECL_API int ecl_stream_to_handle(cl_object s, bool output);
 
 /* finalize.c */
 
+extern ECL_API void ecl_set_finalizer_unprotected(cl_object o, cl_object finalizer);
 extern ECL_API cl_object si_get_finalizer(cl_object o);
 extern ECL_API cl_object si_set_finalizer(cl_object o, cl_object finalizer);