diff --git a/tests/snippets/sysmod.py b/tests/snippets/sysmod.py
index adabb57d2b..7c97846f18 100644
--- a/tests/snippets/sysmod.py
+++ b/tests/snippets/sysmod.py
@@ -20,3 +20,4 @@
 assert type(sys.flags).__name__ == "flags"
 assert type(sys.flags.optimize) is int
 assert sys.flags[3] == sys.flags.optimize
+assert sys.maxunicode == 1114111
diff --git a/vm/src/sysmodule.rs b/vm/src/sysmodule.rs
index 95ac3bd1ff..ce033001d6 100644
--- a/vm/src/sysmodule.rs
+++ b/vm/src/sysmodule.rs
@@ -256,7 +256,8 @@ settrace() -- set the global debug tracing function
       "getfilesystemencoding" => ctx.new_rustfunc(sys_getfilesystemencoding),
       "getfilesystemencodeerrors" => ctx.new_rustfunc(sys_getfilesystemencodeerrors),
       "intern" => ctx.new_rustfunc(sys_intern),
-      "maxsize" => ctx.new_int(std::usize::MAX),
+      "maxunicode" => ctx.new_int(0x0010_FFFF),
+      "maxsize" => ctx.new_int(std::isize::MAX),
       "path" => path,
       "ps1" => ctx.new_str(">>>>> ".to_string()),
       "ps2" => ctx.new_str("..... ".to_string()),