diff --git a/src/flake8/utils.py b/src/flake8/utils.py
index 6bf0b49..5db1d22 100644
--- a/src/flake8/utils.py
+++ b/src/flake8/utils.py
@@ -197,7 +197,9 @@ def normalize_path(path, parent=os.curdir):
     return path.rstrip(separator + alternate_separator)
 
 
-def _stdin_get_value_py3():  # type: () -> str
+@functools.lru_cache(maxsize=1)
+def stdin_get_value():  # type: () -> str
+    """Get and cache it so plugins can use it."""
     stdin_value = sys.stdin.buffer.read()
     fd = io.BytesIO(stdin_value)
     try:
@@ -208,12 +210,6 @@ def _stdin_get_value_py3():  # type: () -> str
         return stdin_value.decode("utf-8")
 
 
-@functools.lru_cache(maxsize=1)
-def stdin_get_value():  # type: () -> str
-    """Get and cache it so plugins can use it."""
-    return _stdin_get_value_py3()
-
-
 def stdin_get_lines():  # type: () -> List[str]
     """Return lines of stdin split according to file splitting."""
     return list(io.StringIO(stdin_get_value()))