diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 6cf5cb2..e45f3d7 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -3241,6 +3241,11 @@
         return NULL;
     }
 
+    if (PyErr_WarnEx(PyExc_DeprecationWarning,
+                     "PyUnicode_AsDecodedObject() is deprecated; "
+                     "use PyCodec_Decode() to decode from str", 1) < 0)
+        return NULL;
+
     if (encoding == NULL)
         encoding = PyUnicode_GetDefaultEncoding();
 
@@ -3260,6 +3265,11 @@
         goto onError;
     }
 
+    if (PyErr_WarnEx(PyExc_DeprecationWarning,
+                     "PyUnicode_AsDecodedUnicode() is deprecated; "
+                     "use PyCodec_Decode() to decode from str to str", 1) < 0)
+        return NULL;
+
     if (encoding == NULL)
         encoding = PyUnicode_GetDefaultEncoding();
 
@@ -3310,6 +3320,12 @@
         goto onError;
     }
 
+    if (PyErr_WarnEx(PyExc_DeprecationWarning,
+                     "PyUnicode_AsEncodedObject() is deprecated; "
+                     "use PyUnicode_AsEncodedString() to encode from str to bytes "
+                     "or PyCodec_Encode() for generic encoding", 1) < 0)
+        return NULL;
+
     if (encoding == NULL)
         encoding = PyUnicode_GetDefaultEncoding();
 
@@ -3635,6 +3651,11 @@
         goto onError;
     }
 
+    if (PyErr_WarnEx(PyExc_DeprecationWarning,
+                     "PyUnicode_AsEncodedUnicode() is deprecated; "
+                     "use PyCodec_Encode() to encode from str to str", 1) < 0)
+        return NULL;
+
     if (encoding == NULL)
         encoding = PyUnicode_GetDefaultEncoding();