diff --git a/artiq/protocols/pyon.py b/artiq/protocols/pyon.py
index 28ee7e904..20a89e355 100644
--- a/artiq/protocols/pyon.py
+++ b/artiq/protocols/pyon.py
@@ -40,6 +40,7 @@ _encode_map = {
     list: "list",
     set: "set",
     dict: "dict",
+    slice: "slice",
     wrapping_int: "number",
     Fraction: "fraction",
     OrderedDict: "ordereddict",
@@ -134,6 +135,9 @@ class _Encoder:
         r += "}"
         return r
 
+    def encode_slice(self, x):
+        return repr(x)
+
     def encode_fraction(self, x):
         return "Fraction({}, {})".format(self.encode(x.numerator),
                                          self.encode(x.denominator))
@@ -186,6 +190,7 @@ _eval_dict = {
     "null": None,
     "false": False,
     "true": True,
+    "slice": slice,
 
     "int": wrapping_int,
     "Fraction": Fraction,
diff --git a/artiq/test/test_serialization.py b/artiq/test/test_serialization.py
index 369c36fd2..e54234e00 100644
--- a/artiq/test/test_serialization.py
+++ b/artiq/test/test_serialization.py
@@ -9,6 +9,7 @@ from artiq.protocols import pyon
 
 _pyon_test_object = {
     (1, 2): [(3, 4.2), (2, )],
+    "slice": slice(3),
     Fraction(3, 4): np.linspace(5, 10, 1),
     "set": {"testing", "sets"},
     "a": np.int8(9), "b": np.int16(-98), "c": np.int32(42), "d": np.int64(-5),
diff --git a/artiq/test/test_sync_struct.py b/artiq/test/test_sync_struct.py
index e5e950535..fbc199e0f 100644
--- a/artiq/test/test_sync_struct.py
+++ b/artiq/test/test_sync_struct.py
@@ -18,6 +18,7 @@ def write_test_data(test_dict):
         test_dict[key] = value
     test_dict[1.5] = 1.5
     test_dict["list"] = []
+    test_dict["list"][:] = [34, 31]
     test_dict["list"].append(42)
     test_dict["list"].insert(1, 1)
     test_dict[100] = 0