diff --git a/artiq/compiler/transforms/inferencer.py b/artiq/compiler/transforms/inferencer.py
index 194c3832d..9a3cbd0ed 100644
--- a/artiq/compiler/transforms/inferencer.py
+++ b/artiq/compiler/transforms/inferencer.py
@@ -396,7 +396,8 @@ class Inferencer(algorithm.Visitor):
                     self._unify(left.type, right.type,
                                 left.loc, right.loc)
                     return left.type, left.type, right.type
-            elif builtins.is_str(left.type) or builtins.is_str(right.type):
+            elif (builtins.is_str(left.type) or builtins.is_str(right.type) or
+                  builtins.is_bytes(left.type) or builtins.is_bytes(right.type)):
                 self._unify(left.type, right.type,
                             left.loc, right.loc)
                 return left.type, left.type, right.type
diff --git a/artiq/test/lit/integration/bytes.py b/artiq/test/lit/integration/bytes.py
new file mode 100644
index 000000000..da68591e2
--- /dev/null
+++ b/artiq/test/lit/integration/bytes.py
@@ -0,0 +1,5 @@
+# RUN: %python -m artiq.compiler.testbench.jit %s
+# RUN: %python %s
+
+assert b"xy" == b"xy"
+assert (b"x" + b"y") == b"xy"