diff --git a/artiq/protocols/pyon.py b/artiq/protocols/pyon.py
index 8c4afbbdc..238ff2198 100644
--- a/artiq/protocols/pyon.py
+++ b/artiq/protocols/pyon.py
@@ -74,7 +74,10 @@ class _Encoder:
 
     def encode_str(self, x):
         # Do not use repr() for JSON compatibility.
-        tt = {ord("\""): "\\\"", ord("\\"): "\\\\", ord("\n"): "\\n"}
+        tt = {
+              ord("\""): "\\\"", ord("\\"): "\\\\",
+              ord("\n"): "\\n", ord("\r"): "\\r"
+        }
         return "\"" + x.translate(tt) + "\""
 
     def encode_bytes(self, x):
diff --git a/artiq/test/serialization.py b/artiq/test/serialization.py
index 7bcbed5eb..88cf9b18e 100644
--- a/artiq/test/serialization.py
+++ b/artiq/test/serialization.py
@@ -26,7 +26,7 @@ class PYON(unittest.TestCase):
 _json_test_object = {
     "a": "b",
     "x": [1, 2, {}],
-    "foo\nbaz\\qux\"": ["bar", 1.2, {"x": "y"}],
+    "foo\nbaz\\qux\"\r2": ["bar", 1.2, {"x": "y"}],
     "bar": [True, False, None]
 }