diff --git a/src/lisp/gc.h b/src/lisp/gc.h
index a75cadd..8623cba 100644
--- a/src/lisp/gc.h
+++ b/src/lisp/gc.h
@@ -11,3 +11,4 @@
 void _do_gc(unsigned int esp, unsigned int ebp);
 void _mark(value_t value, unsigned int *marked);
 void _sweep();
+void free_all();