diff --git a/starlette/middleware/wsgi.py b/starlette/middleware/wsgi.py
index fbc8411bf..8f7d92711 100644
--- a/starlette/middleware/wsgi.py
+++ b/starlette/middleware/wsgi.py
@@ -13,8 +13,8 @@ def build_environ(scope: Scope, body: bytes) -> dict:
     """
     environ = {
         "REQUEST_METHOD": scope["method"],
-        "SCRIPT_NAME": scope.get("root_path", ""),
-        "PATH_INFO": scope["path"],
+        "SCRIPT_NAME": scope.get("root_path", "").encode("utf8").decode("latin1"),
+        "PATH_INFO": scope["path"].encode("utf8").decode("latin1"),
         "QUERY_STRING": scope["query_string"].decode("ascii"),
         "SERVER_PROTOCOL": f"HTTP/{scope['http_version']}",
         "wsgi.version": (1, 0),
diff --git a/tests/middleware/test_wsgi.py b/tests/middleware/test_wsgi.py
index 202726097..c35fda426 100644
--- a/tests/middleware/test_wsgi.py
+++ b/tests/middleware/test_wsgi.py
@@ -128,3 +128,18 @@ def test_build_environ():
         "wsgi.url_scheme": "https",
         "wsgi.version": (1, 0),
     }
+
+
+def test_build_environ_encoding() -> None:
+    scope = {
+        "type": "http",
+        "http_version": "1.1",
+        "method": "GET",
+        "path": "/小星",
+        "root_path": "/中国",
+        "query_string": b"a=123&b=456",
+        "headers": [],
+    }
+    environ = build_environ(scope, b"")
+    assert environ["SCRIPT_NAME"] == "/中国".encode("utf8").decode("latin-1")
+    assert environ["PATH_INFO"] == "/小星".encode("utf8").decode("latin-1")