diff --git a/src/lru.h b/src/lru.h
index 8b515bc04..c5a9bb994 100644
--- a/src/lru.h
+++ b/src/lru.h
@@ -39,7 +39,7 @@ class lru_cache_t {
         lru_node_t(lru_node_t &&) = default;
 
         // Our key in the map. This is owned by the map itself.
-        const wcstring *key;
+        const wcstring *key = NULL;
 
         // The value from the client
         CONTENTS value;