diff --git a/py/objgenerator.c b/py/objgenerator.c
index 8cb0e60ccb..9d6e636b38 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -74,6 +74,7 @@ const mp_obj_type_t mp_type_gen_wrap = {
     { &mp_type_type },
     .name = MP_QSTR_generator,
     .call = gen_wrap_call,
+    .unary_op = mp_generic_unary_op,
 };
 
 mp_obj_t mp_obj_new_gen_wrap(mp_obj_t fun) {
@@ -235,6 +236,7 @@ const mp_obj_type_t mp_type_gen_instance = {
     { &mp_type_type },
     .name = MP_QSTR_generator,
     .print = gen_instance_print,
+    .unary_op = mp_generic_unary_op,
     .getiter = mp_identity_getiter,
     .iternext = gen_instance_iternext,
     .locals_dict = (mp_obj_dict_t*)&gen_instance_locals_dict,
diff --git a/tests/basics/builtin_hash_gen.py b/tests/basics/builtin_hash_gen.py
new file mode 100644
index 0000000000..d42e5ebfbc
--- /dev/null
+++ b/tests/basics/builtin_hash_gen.py
@@ -0,0 +1,7 @@
+# test builtin hash function, on generators
+
+def gen():
+    yield
+
+print(type(hash(gen)))
+print(type(hash(gen())))
diff --git a/tests/run-tests b/tests/run-tests
index f651242862..bd4a1363cb 100755
--- a/tests/run-tests
+++ b/tests/run-tests
@@ -323,6 +323,7 @@ def run_tests(pyb, tests, args, base_path="."):
         skip_tests.update({'basics/%s.py' % t for t in 'with_break with_continue with_return'.split()}) # require complete with support
         skip_tests.add('basics/array_construct2.py') # requires generators
         skip_tests.add('basics/bool1.py') # seems to randomly fail
+        skip_tests.add('basics/builtin_hash_gen.py') # requires yield
         skip_tests.add('basics/class_bind_self.py') # requires yield
         skip_tests.add('basics/del_deref.py') # requires checking for unbound local
         skip_tests.add('basics/del_local.py') # requires checking for unbound local