diff --git a/lazy.h b/lazy.h
index ada0504..768423d 100644
--- a/lazy.h
+++ b/lazy.h
@@ -265,6 +265,15 @@ long long lz_sb_atoll(Lz_SB *src);
 } while(0)
 #endif
 
+#ifndef lz_hm_destroy 
+#define lz_hm_destroy(hm, k) do {\
+  free((hm).keys);\
+  free((hm).vals);\
+  free((hm).exists);\
+  free((hm).tombstones);\
+} while(0)
+#endif
+
 #ifdef LAZY_IMPL
 #undef LAZY_IMPL
 size_t lz_hm_hash_raw_bytes(size_t cap, void *key, size_t k_s) {