diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 4bed0dc..8182ae2 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -153,7 +153,7 @@
 					    NULL))
 			return NULL;
 		s = s_buffer;
-		len = strlen(s);
+		len = (int)strlen(s);
 	}
 	else if (PyObject_AsCharBuffer(v, &s, &len)) {
 		PyErr_SetString(PyExc_TypeError,