diff --git a/pygmt/src/filter1d.py b/pygmt/src/filter1d.py
index 4bd0cdf8344..3bb08cf6ff2 100644
--- a/pygmt/src/filter1d.py
+++ b/pygmt/src/filter1d.py
@@ -4,8 +4,8 @@
 
 from typing import Literal
 
+import numpy as np
 import pandas as pd
-import xarray as xr
 from pygmt.clib import Session
 from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import (
@@ -27,7 +27,7 @@ def filter1d(
     output_type: Literal["pandas", "numpy", "file"] = "pandas",
     outfile: str | None = None,
     **kwargs,
-) -> pd.DataFrame | xr.DataArray | None:
+) -> pd.DataFrame | np.ndarray | None:
     r"""
     Time domain filtering of 1-D data tables.
 
diff --git a/pygmt/src/grd2xyz.py b/pygmt/src/grd2xyz.py
index 17cfcb246bc..ea1c52cb224 100644
--- a/pygmt/src/grd2xyz.py
+++ b/pygmt/src/grd2xyz.py
@@ -4,6 +4,7 @@
 
 from typing import TYPE_CHECKING, Literal
 
+import numpy as np
 import pandas as pd
 import xarray as xr
 from pygmt.clib import Session
@@ -42,7 +43,7 @@ def grd2xyz(
     output_type: Literal["pandas", "numpy", "file"] = "pandas",
     outfile: str | None = None,
     **kwargs,
-) -> pd.DataFrame | xr.DataArray | None:
+) -> pd.DataFrame | np.ndarray | None:
     r"""
     Convert grid to data table.