diff --git a/fastparquet/api.py b/fastparquet/api.py
index f6e55426..c54e5eb5 100644
--- a/fastparquet/api.py
+++ b/fastparquet/api.py
@@ -993,7 +993,7 @@ def _dtypes(self, categories=None):
                         if self.pandas_nulls:
                             dtype[col] = converted_types.nullable[dt]
                         else:
-                            dtype[col] = np.float_()
+                            dtype[col] = np.float64()
                 elif dt == 'S12':
                     dtype[col] = 'M8[ns]'
             self._base_dtype = dtype