diff --git a/Modules/_testcapi/clinic/float.c.h b/Modules/_testcapi/clinic/float.c.h
new file mode 100644
index 00000000000000..c1dff2a9ac5789
--- /dev/null
+++ b/Modules/_testcapi/clinic/float.c.h
@@ -0,0 +1,88 @@
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+#if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+#  include "pycore_gc.h"            // PyGC_Head
+#  include "pycore_runtime.h"       // _Py_ID()
+#endif
+
+
+PyDoc_STRVAR(_testcapi_float_pack__doc__,
+"float_pack($module, size, d, le, /)\n"
+"--\n"
+"\n"
+"Test PyFloat_Pack2(), PyFloat_Pack4() and PyFloat_Pack8()");
+
+#define _TESTCAPI_FLOAT_PACK_METHODDEF    \
+    {"float_pack", _PyCFunction_CAST(_testcapi_float_pack), METH_FASTCALL, _testcapi_float_pack__doc__},
+
+static PyObject *
+_testcapi_float_pack_impl(PyObject *module, int size, double d, int le);
+
+static PyObject *
+_testcapi_float_pack(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    int size;
+    double d;
+    int le;
+
+    if (!_PyArg_CheckPositional("float_pack", nargs, 3, 3)) {
+        goto exit;
+    }
+    size = _PyLong_AsInt(args[0]);
+    if (size == -1 && PyErr_Occurred()) {
+        goto exit;
+    }
+    if (PyFloat_CheckExact(args[1])) {
+        d = PyFloat_AS_DOUBLE(args[1]);
+    }
+    else
+    {
+        d = PyFloat_AsDouble(args[1]);
+        if (d == -1.0 && PyErr_Occurred()) {
+            goto exit;
+        }
+    }
+    le = _PyLong_AsInt(args[2]);
+    if (le == -1 && PyErr_Occurred()) {
+        goto exit;
+    }
+    return_value = _testcapi_float_pack_impl(module, size, d, le);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(_testcapi_float_unpack__doc__,
+"float_unpack($module, data, le, /)\n"
+"--\n"
+"\n"
+"Test PyFloat_Unpack2(), PyFloat_Unpack4() and PyFloat_Unpack8()");
+
+#define _TESTCAPI_FLOAT_UNPACK_METHODDEF    \
+    {"float_unpack", _PyCFunction_CAST(_testcapi_float_unpack), METH_FASTCALL, _testcapi_float_unpack__doc__},
+
+static PyObject *
+_testcapi_float_unpack_impl(PyObject *module, const char *data,
+                            Py_ssize_t data_length, int le);
+
+static PyObject *
+_testcapi_float_unpack(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    const char *data;
+    Py_ssize_t data_length;
+    int le;
+
+    if (!_PyArg_ParseStack(args, nargs, "y#i:float_unpack",
+        &data, &data_length, &le)) {
+        goto exit;
+    }
+    return_value = _testcapi_float_unpack_impl(module, data, data_length, le);
+
+exit:
+    return return_value;
+}
+/*[clinic end generated code: output=083e5df26cd5fbeb input=a9049054013a1b77]*/
diff --git a/Modules/_testcapi/float.c b/Modules/_testcapi/float.c
index 26d99d990e0042..33cbda83a81af7 100644
--- a/Modules/_testcapi/float.c
+++ b/Modules/_testcapi/float.c
@@ -1,18 +1,29 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "parts.h"
+#include "clinic/float.c.h"
 
 
-// Test PyFloat_Pack2(), PyFloat_Pack4() and PyFloat_Pack8()
+/*[clinic input]
+module _testcapi
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=6361033e795369fc]*/
+
+/*[clinic input]
+_testcapi.float_pack
+
+    size: int
+    d: double
+    le: int
+    /
+
+Test PyFloat_Pack2(), PyFloat_Pack4() and PyFloat_Pack8()
+[clinic start generated code]*/
+
 static PyObject *
-test_float_pack(PyObject *self, PyObject *args)
+_testcapi_float_pack_impl(PyObject *module, int size, double d, int le)
+/*[clinic end generated code: output=7899bd98f8b6cb04 input=52c9115121999c98]*/
 {
-    int size;
-    double d;
-    int le;
-    if (!PyArg_ParseTuple(args, "idi", &size, &d, &le)) {
-        return NULL;
-    }
     switch (size)
     {
     case 2:
@@ -47,19 +58,24 @@ test_float_pack(PyObject *self, PyObject *args)
 }
 
 
-// Test PyFloat_Unpack2(), PyFloat_Unpack4() and PyFloat_Unpack8()
+/*[clinic input]
+_testcapi.float_unpack
+
+    data: str(accept={robuffer}, zeroes=True)
+    le: int
+    /
+
+Test PyFloat_Unpack2(), PyFloat_Unpack4() and PyFloat_Unpack8()
+[clinic start generated code]*/
+
 static PyObject *
-test_float_unpack(PyObject *self, PyObject *args)
+_testcapi_float_unpack_impl(PyObject *module, const char *data,
+                            Py_ssize_t data_length, int le)
+/*[clinic end generated code: output=617059f889ddbfe4 input=c095e4bb75a696cd]*/
 {
     assert(!PyErr_Occurred());
-    const char *data;
-    Py_ssize_t size;
-    int le;
-    if (!PyArg_ParseTuple(args, "y#i", &data, &size, &le)) {
-        return NULL;
-    }
     double d;
-    switch (size)
+    switch (data_length)
     {
     case 2:
         d = PyFloat_Unpack2(data, le);
@@ -82,8 +98,8 @@ test_float_unpack(PyObject *self, PyObject *args)
 }
 
 static PyMethodDef test_methods[] = {
-    {"float_pack", test_float_pack, METH_VARARGS, NULL},
-    {"float_unpack", test_float_unpack, METH_VARARGS, NULL},
+    _TESTCAPI_FLOAT_PACK_METHODDEF
+    _TESTCAPI_FLOAT_UNPACK_METHODDEF
     {NULL},
 };