1 files changed, 1 insertions, 0 deletions
diff --git a/array.c b/array.c
index 0357e728f0..e3d92bac2d 100644
--- a/array.c
+++ b/array.c
@@ -3124,6 +3124,7 @@ flatten(ary, level, modified)
 		*modified = 1;
 		id = (st_data_t)tmp;
 		if (st_lookup(memo, id, 0)) {
+		    st_free_table(memo);
 		    rb_raise(rb_eArgError, "tried to flatten recursive array");
 		}
 		st_insert(memo, id, (st_data_t)Qtrue);