diff --git a/src/if_python3.c b/src/if_python3.c
index 5d87fa3..4f6809d 100644
--- a/src/if_python3.c
+++ b/src/if_python3.c
@@ -96,6 +96,7 @@
 #define PyInt_FromLong(i) PyLong_FromLong(i)
 #define PyInt_AsLong(obj) PyLong_AsLong(obj)
 #define Py_ssize_t_fmt "n"
+#define Py_bytes_fmt "y"
 
 #if defined(DYNAMIC_PYTHON3) || defined(PROTO)
 
@@ -149,6 +150,7 @@
 # define PySequence_Check py3_PySequence_Check
 # define PySequence_Size py3_PySequence_Size
 # define PySequence_GetItem py3_PySequence_GetItem
+# define PySequence_Fast py3_PySequence_Fast
 # define PyTuple_Size py3_PyTuple_Size
 # define PyTuple_GetItem py3_PyTuple_GetItem
 # define PySlice_GetIndicesEx py3_PySlice_GetIndicesEx
@@ -168,6 +170,7 @@
 #undef PyRun_String
 # define PyRun_String py3_PyRun_String
 # define PyObject_GetAttrString py3_PyObject_GetAttrString
+# define PyObject_HasAttrString py3_PyObject_HasAttrString
 # define PyObject_SetAttrString py3_PyObject_SetAttrString
 # define PyObject_CallFunctionObjArgs py3_PyObject_CallFunctionObjArgs
 # define PyEval_GetLocals py3_PyEval_GetLocals
@@ -269,6 +272,7 @@
 static int (*py3_PySequence_Check)(PyObject *);
 static Py_ssize_t (*py3_PySequence_Size)(PyObject *);
 static PyObject* (*py3_PySequence_GetItem)(PyObject *, Py_ssize_t);
+static PyObject* (*py3_PySequence_Fast)(PyObject *, const char *);
 static Py_ssize_t (*py3_PyTuple_Size)(PyObject *);
 static PyObject* (*py3_PyTuple_GetItem)(PyObject *, Py_ssize_t);
 static int (*py3_PyMapping_Check)(PyObject *);
@@ -282,6 +286,7 @@
 static int (*py3_PyRun_SimpleString)(char *);
 static PyObject* (*py3_PyRun_String)(char *, int, PyObject *, PyObject *);
 static PyObject* (*py3_PyObject_GetAttrString)(PyObject *, const char *);
+static int (*py3_PyObject_HasAttrString)(PyObject *, const char *);
 static PyObject* (*py3_PyObject_SetAttrString)(PyObject *, const char *, PyObject *);
 static PyObject* (*py3_PyObject_CallFunctionObjArgs)(PyObject *, ...);
 static PyObject* (*py3_PyEval_GetGlobals)();
@@ -425,6 +430,7 @@
     {"PySequence_Check", (PYTHON_PROC*)&py3_PySequence_Check},
     {"PySequence_Size", (PYTHON_PROC*)&py3_PySequence_Size},
     {"PySequence_GetItem", (PYTHON_PROC*)&py3_PySequence_GetItem},
+    {"PySequence_Fast", (PYTHON_PROC*)&py3_PySequence_Fast},
     {"PyTuple_Size", (PYTHON_PROC*)&py3_PyTuple_Size},
     {"PyTuple_GetItem", (PYTHON_PROC*)&py3_PyTuple_GetItem},
     {"PySlice_GetIndicesEx", (PYTHON_PROC*)&py3_PySlice_GetIndicesEx},
@@ -435,6 +441,7 @@
     {"PyRun_SimpleString", (PYTHON_PROC*)&py3_PyRun_SimpleString},
     {"PyRun_String", (PYTHON_PROC*)&py3_PyRun_String},
     {"PyObject_GetAttrString", (PYTHON_PROC*)&py3_PyObject_GetAttrString},
+    {"PyObject_HasAttrString", (PYTHON_PROC*)&py3_PyObject_HasAttrString},
     {"PyObject_SetAttrString", (PYTHON_PROC*)&py3_PyObject_SetAttrString},
     {"PyObject_CallFunctionObjArgs", (PYTHON_PROC*)&py3_PyObject_CallFunctionObjArgs},
     {"PyEval_GetGlobals", (PYTHON_PROC*)&py3_PyEval_GetGlobals},