diff --git a/Lib/_pydatetime.py b/Lib/_pydatetime.py
index bca2acf1fc88cf..533973d24b0eab 100644
--- a/Lib/_pydatetime.py
+++ b/Lib/_pydatetime.py
@@ -970,7 +970,7 @@ def __new__(cls, year, month=None, day=None):
     @classmethod
     def fromtimestamp(cls, t):
         "Construct a date from a POSIX timestamp (like time.time())."
-        y, m, d, hh, mm, ss, weekday, jday, dst = _time.localtime(t)
+        y, m, d, hh, mm, ss, weekday, jday, dst = _time.localtime(float(t))
         return cls(y, m, d)
 
     @classmethod
@@ -1808,6 +1808,7 @@ def fromtimestamp(cls, timestamp, tz=None):
     @classmethod
     def utcfromtimestamp(cls, t):
         """Construct a naive UTC datetime from a POSIX timestamp."""
+        t = float(t)
         import warnings
         warnings.warn("datetime.utcfromtimestamp() is deprecated and scheduled "
                       "for removal in a future version. Use timezone-aware "