1 files changed, 2 insertions, 0 deletions
diff --git a/eval.c b/eval.c
index 215d562f..099c1327 100644
--- a/eval.c
+++ b/eval.c
@@ -4636,6 +4636,8 @@ void eval_init(void)
   reg_fun(intern(lit("hash-subset"), user_package), func_n2(hash_subset));
   reg_fun(intern(lit("hash-proper-subset"), user_package), func_n2(hash_proper_subset));
   reg_fun(intern(lit("group-by"), user_package), func_n2v(group_by));
+  reg_fun(intern(lit("group-reduce"), user_package),
+          func_n6o(group_reduce, 4));
   reg_fun(intern(lit("sort-group"), user_package), func_n3o(sort_group, 1));
   reg_fun(intern(lit("unique"), user_package), func_n2ov(unique, 1));
   reg_fun(intern(lit("uniq"), user_package), func_n1(uniq));