diff --git a/Modules/_gdbmmodule.c b/Modules/_gdbmmodule.c
index 4404d2f..6c75819 100644
--- a/Modules/_gdbmmodule.c
+++ b/Modules/_gdbmmodule.c
@@ -130,7 +130,7 @@
         PyErr_SetObject(PyExc_KeyError, key);
         return NULL;
     }
-    v = PyString_FromStringAndSize(drec.dptr, drec.dsize);
+    v = PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
     free(drec.dptr);
     return v;
 }
@@ -220,7 +220,7 @@
 
     key = gdbm_firstkey(dp->di_dbm);
     while (key.dptr) {
-        item = PyString_FromStringAndSize(key.dptr, key.dsize);
+        item = PyBytes_FromStringAndSize(key.dptr, key.dsize);
         if (item == NULL) {
             free(key.dptr);
             Py_DECREF(v);
@@ -251,14 +251,14 @@
 			"GDBM object has already been closed");
 	return -1;
     }
-    if (!PyString_Check(arg)) {
+    if (!PyBytes_Check(arg)) {
 	PyErr_Format(PyExc_TypeError,
 		     "gdbm key must be bytes, not %.100s",
 		     arg->ob_type->tp_name);
 	return -1;
     }
-    key.dptr = PyString_AS_STRING(arg);
-    key.dsize = PyString_GET_SIZE(arg);
+    key.dptr = PyBytes_AS_STRING(arg);
+    key.dsize = PyBytes_GET_SIZE(arg);
     return gdbm_exists(dp->di_dbm, key);
 }
 
@@ -291,7 +291,7 @@
     check_dbmobject_open(dp);
     key = gdbm_firstkey(dp->di_dbm);
     if (key.dptr) {
-        v = PyString_FromStringAndSize(key.dptr, key.dsize);
+        v = PyBytes_FromStringAndSize(key.dptr, key.dsize);
         free(key.dptr);
         return v;
     }
@@ -323,7 +323,7 @@
     check_dbmobject_open(dp);
     nextkey = gdbm_nextkey(dp->di_dbm, key);
     if (nextkey.dptr) {
-        v = PyString_FromStringAndSize(nextkey.dptr, nextkey.dsize);
+        v = PyBytes_FromStringAndSize(nextkey.dptr, nextkey.dsize);
         free(nextkey.dptr);
         return v;
     }