diff --git a/pandas/core/arrays/datetimes.py b/pandas/core/arrays/datetimes.py
index d2c2811759e7c..1265bb469d7eb 100644
--- a/pandas/core/arrays/datetimes.py
+++ b/pandas/core/arrays/datetimes.py
@@ -2231,8 +2231,10 @@ def maybe_convert_dtype(data, copy: bool, tz: tzinfo | None = None):
 
     if is_float_dtype(data.dtype):
         # pre-2.0 we treated these as wall-times, inconsistent with ints
-        # GH#23675, GH#45573 deprecated to treat symmetrically with integer dtypes
-        data = data.astype(np.int64)
+        # GH#23675, GH#45573 deprecated to treat symmetrically with integer dtypes.
+        # Note: data.astype(np.int64) fails ARM tests, see
+        # https://github.com/pandas-dev/pandas/issues/49468.
+        data = data.astype("M8[ns]").view("i8")
         copy = False
 
     elif is_timedelta64_dtype(data.dtype) or is_bool_dtype(data.dtype):