diff --git a/tile.cc b/tile.cc
index e7b18201..ce09b876 100644
--- a/tile.cc
+++ b/tile.cc
@@ -511,7 +511,7 @@ long long write_tile(struct index *start, struct index *end, char *metabase, uns
 	}
 
 	int nfeatures = 0;
-	struct coalesce features[end - start];
+	struct coalesce *features = (struct coalesce *) malloc((end - start) * sizeof(struct coalesce));
 
 	struct index *i;
 	for (i = start; i < end; i++) {
@@ -642,6 +642,8 @@ long long write_tile(struct index *start, struct index *end, char *metabase, uns
 		free(features[x].meta);
 	}
 
+	free(features);
+
 	struct pool_val *pv;
 	for (pv = keys.head; pv != NULL; pv = pv->next) {
 		layer->add_keys(pv->s, strlen(pv->s));