diff --git a/RISCOS/Modules/drawfmodule.c b/RISCOS/Modules/drawfmodule.c
index 5f8dc3e..61aadd3 100644
--- a/RISCOS/Modules/drawfmodule.c
+++ b/RISCOS/Modules/drawfmodule.c
@@ -333,7 +333,7 @@
   char *dtable;
   if(!PyArg_ParseTuple(arg,"O!",&PyDict_Type,&d)) return NULL;
   while(PyDict_Next(d,&n,&key,&value))
-  { int m=PyString_Size(value);
+  { int m=PyBytes_Size(value);
     if(m<0||!PyInt_Check(key)) return NULL;
     size+=m+2;
   }
@@ -350,9 +350,9 @@
   memset(dtable,0,size-8);
   n=0;
   while(PyDict_Next(d,&n,&key,&value))
-  { int m=PyString_Size(value);
+  { int m=PyBytes_Size(value);
     *dtable=(char)PyInt_AsLong(key);
-    strcpy(dtable+1,PyString_AsString(value));
+    strcpy(dtable+1,PyBytes_AsString(value));
     dtable+=m+2;
   }
   Py_INCREF(Py_None);return Py_None;
@@ -609,8 +609,8 @@
   if (!strcmp(name, "__members__"))
   { PyObject *list = PyList_New(2);
     if (list)
-    { PyList_SetItem(list, 0, PyString_FromString("size"));
-      PyList_SetItem(list, 1, PyString_FromString("start"));
+    { PyList_SetItem(list, 0, PyBytes_FromString("size"));
+      PyList_SetItem(list, 1, PyBytes_FromString("start"));
       if (PyErr_Occurred()) { Py_DECREF(list);list = NULL;}
     }
     return list;
@@ -659,6 +659,6 @@
 { PyObject *m, *d;
   m = Py_InitModule("drawf", DrawFMethods);
   d = PyModule_GetDict(m);
-  DrawFError=PyString_FromString("drawf.error");
+  DrawFError=PyBytes_FromString("drawf.error");
   PyDict_SetItemString(d,"error",DrawFError);
 }
diff --git a/RISCOS/Modules/riscosmodule.c b/RISCOS/Modules/riscosmodule.c
index 3dabb4d..cf37e18 100644
--- a/RISCOS/Modules/riscosmodule.c
+++ b/RISCOS/Modules/riscosmodule.c
@@ -79,9 +79,9 @@
   char *buf;
   e=xosfscontrol_canonicalise_path(path,0,0,0,0,&len);
   if(e) return riscos_oserror();
-  obj=PyString_FromStringAndSize(NULL,-len);
+  obj=PyBytes_FromStringAndSize(NULL,-len);
   if(obj==NULL) return NULL;
-  buf=PyString_AsString(obj);
+  buf=PyBytes_AsString(obj);
   e=xosfscontrol_canonicalise_path(path,buf,0,0,1-len,&len);
   if(len!=1) return riscos_error("Error expanding path");
   if(!e) return obj;
@@ -131,7 +131,7 @@
 	  { Py_DECREF(d);return riscos_oserror();
 	  }
 	  if(count)
-	  { v=PyString_FromString(buf);
+	  { v=PyBytes_FromString(buf);
 	    if(!v) { Py_DECREF(d);return 0;}
 	    if(PyList_Append(d,v)) {Py_DECREF(d);Py_DECREF(v);return 0;}
 	  }
@@ -320,7 +320,7 @@
   char *name,*value;
   if(!PyArg_ParseTuple(args,"s:getenv",&name)) return NULL;
   value=getenv(name);
-  if(value) return PyString_FromString(value);
+  if(value) return PyBytes_FromString(value);
   Py_INCREF(Py_None);
   return Py_None;
 }
@@ -371,7 +371,7 @@
          os_VARTYPE_EXPANDED,&size,(int *)&context,0))
   { PyObject *v;
     value[size]='\0';
-    v = PyString_FromString(value);
+    v = PyBytes_FromString(value);
     if (v == NULL) continue;
     PyDict_SetItemString(dict, context, v);
     Py_DECREF(v);
diff --git a/RISCOS/Modules/swimodule.c b/RISCOS/Modules/swimodule.c
index b241276..18be42e 100644
--- a/RISCOS/Modules/swimodule.c
+++ b/RISCOS/Modules/swimodule.c
@@ -66,10 +66,10 @@
   b->length=4*size;
   b->heap=1;
   if(init)
-  { if(PyString_Check(init))
-    { int n=PyString_Size(init);
+  { if(PyBytes_Check(init))
+    { int n=PyBytes_Size(init);
       if (n>4*size) n=4*size;
-      memcpy(b->block,PyString_AsString(init),n);
+      memcpy(b->block,PyBytes_AsString(init),n);
       memset((char*)b->block+n,0,4*size-n);
     }
     else
@@ -113,7 +113,7 @@
   { PyErr_SetString(PyExc_IndexError,"block index out of range");
     return NULL;
   }
-  return PyString_FromStringAndSize((char*)self->block+s,e-s);
+  return PyBytes_FromStringAndSize((char*)self->block+s,e-s);
 }
 
 static PyObject *PyBlock_NullString(PyBlockObject *self,PyObject *arg)
@@ -125,7 +125,7 @@
     return NULL;
   }
   for(i=s;i<e;i++) if(p[i]==0) break;
-  return PyString_FromStringAndSize((char*)self->block+s,i-s);
+  return PyBytes_FromStringAndSize((char*)self->block+s,i-s);
 }
 
 static PyObject *PyBlock_CtrlString(PyBlockObject *self,PyObject *arg)
@@ -137,7 +137,7 @@
     return NULL;
   }
   for(i=s;i<e;i++) if(p[i]<32) break;
-  return PyString_FromStringAndSize((char*)self->block+s,i-s);
+  return PyBytes_FromStringAndSize((char*)self->block+s,i-s);
 }
 
 static PyObject *PyBlock_PadString(PyBlockObject *self,PyObject *arg)
@@ -296,9 +296,9 @@
   if (!strcmp(name, "__members__"))
   { PyObject *list = PyList_New(3);
     if (list)
-    { PyList_SetItem(list, 0, PyString_FromString("length"));
-      PyList_SetItem(list, 1, PyString_FromString("start"));
-      PyList_SetItem(list, 2, PyString_FromString("end"));
+    { PyList_SetItem(list, 0, PyBytes_FromString("length"));
+      PyList_SetItem(list, 1, PyBytes_FromString("start"));
+      PyList_SetItem(list, 2, PyBytes_FromString("end"));
       if (PyErr_Occurred()) { Py_DECREF(list);list = NULL;}
     }
     return list;
@@ -402,7 +402,7 @@
   for(;*fmt;fmt++)
   {  switch(*fmt)
     { case 'i':v=PyInt_FromLong((long)r.r[rno++]); break;
-      case 's':v=PyString_FromString((char*)(r.r[rno++])); break;
+      case 's':v=PyBytes_FromString((char*)(r.r[rno++])); break;
       case '.':rno++; continue;
       case '*':v=PyInt_FromLong((long)carry); break;
     }
@@ -421,7 +421,7 @@
   if(!PyArg_ParseTuple(arg,"i|i",(unsigned int *)&s, &l)) return NULL;
   if (l==-1)
     l = strlen(s);
-  return PyString_FromStringAndSize((char*)s, l);
+  return PyBytes_FromStringAndSize((char*)s, l);
 }
 
 static char swi_string__doc__[] =