diff --git a/pygmt/datatypes/header.py b/pygmt/datatypes/header.py
index a097df19eeb..d7806e50a24 100644
--- a/pygmt/datatypes/header.py
+++ b/pygmt/datatypes/header.py
@@ -3,7 +3,6 @@
 """
 
 import ctypes as ctp
-from enum import IntEnum
 from typing import Any, ClassVar
 
 import numpy as np
@@ -25,40 +24,6 @@
 gmt_grdfloat = ctp.c_float
 
 
-class GMTGridID(IntEnum):
-    """
-    Enum for the GMT grid format ID.
-
-    Defined in gmt_grdio.h.
-    """
-
-    GMT_GRD_UNKNOWN_FMT = 0  # if grid format cannot be auto-detected
-    GMT_GRID_IS_BF = 1  # GMT native, C-binary format (32-bit float)
-    GMT_GRID_IS_BS = 2  # GMT native, C-binary format (16-bit integer)
-    GMT_GRID_IS_RB = 3  # SUN rasterfile format (8-bit standard)
-    GMT_GRID_IS_BB = 4  # GMT native, C-binary format (8-bit integer)
-    GMT_GRID_IS_BM = 5  # GMT native, C-binary format (bit-mask)
-    GMT_GRID_IS_SF = 6  # Golden Software Surfer format 6 (32-bit float)
-    GMT_GRID_IS_CB = 7  # GMT netCDF format (8-bit integer)
-    GMT_GRID_IS_CS = 8  # GMT netCDF format (16-bit integer)
-    GMT_GRID_IS_CI = 9  # GMT netCDF format (32-bit integer)
-    GMT_GRID_IS_CF = 10  # GMT netCDF format (32-bit float)
-    GMT_GRID_IS_CD = 11  # GMT netCDF format (64-bit float)
-    GMT_GRID_IS_RF = 12  # GEODAS grid format GRD98 (NGDC)
-    GMT_GRID_IS_BI = 13  # GMT native, C-binary format (32-bit integer)
-    GMT_GRID_IS_BD = 14  # GMT native, C-binary format (64-bit float)
-    GMT_GRID_IS_NB = 15  # GMT netCDF format (8-bit integer)
-    GMT_GRID_IS_NS = 16  # GMT netCDF format (16-bit integer)
-    GMT_GRID_IS_NI = 17  # GMT netCDF format (32-bit integer)
-    GMT_GRID_IS_NF = 18  # GMT netCDF format (32-bit float)
-    GMT_GRID_IS_ND = 19  # GMT netCDF format (64-bit float)
-    GMT_GRID_IS_SD = 20  # Golden Software Surfer format 7 (64-bit float, read-only)
-    GMT_GRID_IS_AF = 21  # Atlantic Geoscience Center format AGC (32-bit float)
-    GMT_GRID_IS_GD = 22  # Import through GDAL
-    GMT_GRID_IS_EI = 23  # ESRI Arc/Info ASCII Grid Interchange format (ASCII integer)
-    GMT_GRID_IS_EF = 24  # ESRI Arc/Info ASCII Grid Interchange format (ASCII float)
-
-
 def _parse_nameunits(nameunits: str) -> tuple[str, str | None]:
     """
     Get the long_name and units attributes from x_units/y_units/z_units in the grid