diff --git a/pandas/core/generic.py b/pandas/core/generic.py index 298fa75779420..ae5b1180c86f4 100644 --- a/pandas/core/generic.py +++ b/pandas/core/generic.py @@ -172,6 +172,12 @@ def _validate_dtype(self, dtype): raise NotImplementedError("compound dtypes are not implemented" "in the {0} constructor" .format(self.__class__.__name__)) + + # check if coerced dtype is of type object + if dtype.kind == 'O': + raise TypeError("argument 'dtype' must be a valid " + "pandas/numpy dtype") + return dtype def _init_mgr(self, mgr, axes=None, dtype=None, copy=False):