diff --git a/Doc/includes/noddy2.c b/Doc/includes/noddy2.c
index 2caf985..837f270 100644
--- a/Doc/includes/noddy2.c
+++ b/Doc/includes/noddy2.c
@@ -23,14 +23,14 @@
 
     self = (Noddy *)type->tp_alloc(type, 0);
     if (self != NULL) {
-        self->first = PyString_FromString("");
+        self->first = PyBytes_FromString("");
         if (self->first == NULL)
           {
             Py_DECREF(self);
             return NULL;
           }
         
-        self->last = PyString_FromString("");
+        self->last = PyBytes_FromString("");
         if (self->last == NULL)
           {
             Py_DECREF(self);
@@ -90,7 +90,7 @@
     PyObject *args, *result;
 
     if (format == NULL) {
-        format = PyString_FromString("%s %s");
+        format = PyBytes_FromString("%s %s");
         if (format == NULL)
             return NULL;
     }
@@ -109,7 +109,7 @@
     if (args == NULL)
         return NULL;
 
-    result = PyString_Format(format, args);
+    result = PyBytes_Format(format, args);
     Py_DECREF(args);
     
     return result;
diff --git a/Doc/includes/noddy3.c b/Doc/includes/noddy3.c
index 60260ad..5a0a6c1 100644
--- a/Doc/includes/noddy3.c
+++ b/Doc/includes/noddy3.c
@@ -23,14 +23,14 @@
 
     self = (Noddy *)type->tp_alloc(type, 0);
     if (self != NULL) {
-        self->first = PyString_FromString("");
+        self->first = PyBytes_FromString("");
         if (self->first == NULL)
           {
             Py_DECREF(self);
             return NULL;
           }
         
-        self->last = PyString_FromString("");
+        self->last = PyBytes_FromString("");
         if (self->last == NULL)
           {
             Py_DECREF(self);
@@ -93,7 +93,7 @@
     return -1;
   }
   
-  if (! PyString_Check(value)) {
+  if (! PyBytes_Check(value)) {
     PyErr_SetString(PyExc_TypeError, 
                     "The first attribute value must be a string");
     return -1;
@@ -121,7 +121,7 @@
     return -1;
   }
   
-  if (! PyString_Check(value)) {
+  if (! PyBytes_Check(value)) {
     PyErr_SetString(PyExc_TypeError, 
                     "The last attribute value must be a string");
     return -1;
@@ -153,7 +153,7 @@
     PyObject *args, *result;
 
     if (format == NULL) {
-        format = PyString_FromString("%s %s");
+        format = PyBytes_FromString("%s %s");
         if (format == NULL)
             return NULL;
     }
@@ -162,7 +162,7 @@
     if (args == NULL)
         return NULL;
 
-    result = PyString_Format(format, args);
+    result = PyBytes_Format(format, args);
     Py_DECREF(args);
     
     return result;
diff --git a/Doc/includes/noddy4.c b/Doc/includes/noddy4.c
index 878e086..da41b2b 100644
--- a/Doc/includes/noddy4.c
+++ b/Doc/includes/noddy4.c
@@ -57,14 +57,14 @@
 
     self = (Noddy *)type->tp_alloc(type, 0);
     if (self != NULL) {
-        self->first = PyString_FromString("");
+        self->first = PyBytes_FromString("");
         if (self->first == NULL)
           {
             Py_DECREF(self);
             return NULL;
           }
         
-        self->last = PyString_FromString("");
+        self->last = PyBytes_FromString("");
         if (self->last == NULL)
           {
             Py_DECREF(self);
@@ -124,7 +124,7 @@
     PyObject *args, *result;
 
     if (format == NULL) {
-        format = PyString_FromString("%s %s");
+        format = PyBytes_FromString("%s %s");
         if (format == NULL)
             return NULL;
     }
@@ -143,7 +143,7 @@
     if (args == NULL)
         return NULL;
 
-    result = PyString_Format(format, args);
+    result = PyBytes_Format(format, args);
     Py_DECREF(args);
     
     return result;
diff --git a/Doc/includes/run-func.c b/Doc/includes/run-func.c
index 5a7df0d..1b7c942 100644
--- a/Doc/includes/run-func.c
+++ b/Doc/includes/run-func.c
@@ -13,7 +13,7 @@
     }
 
     Py_Initialize();
-    pName = PyString_FromString(argv[1]);
+    pName = PyBytes_FromString(argv[1]);
     /* Error checking of pName left out */
 
     pModule = PyImport_Import(pName);