diff --git a/aiapy/calibrate/meta.py b/aiapy/calibrate/meta.py
index b7f7fe4..67a3f05 100644
--- a/aiapy/calibrate/meta.py
+++ b/aiapy/calibrate/meta.py
@@ -51,7 +51,7 @@ def fix_observer_location(smap):
     return smap._new_instance(smap.data, new_meta, plot_settings=smap.plot_settings, mask=smap.mask)
 
 
-def update_pointing(smap, pointing_table=None):
+def update_pointing(smap, *, pointing_table=None):
     """
     Update pointing information in the `smap` header.
 
diff --git a/aiapy/calibrate/prep.py b/aiapy/calibrate/prep.py
index 4396269..4745cdd 100644
--- a/aiapy/calibrate/prep.py
+++ b/aiapy/calibrate/prep.py
@@ -18,7 +18,7 @@
 
 
 @add_common_docstring(rotation_function_names=_rotation_function_names)
-def register(smap, missing=None, order=3, method="scipy"):
+def register(smap, *, missing=None, order=3, method="scipy"):
     """
     Processes a full-disk level 1 `~sunpy.map.sources.sdo.AIAMap` into a level
     1.5 `~sunpy.map.sources.sdo.AIAMap`.
@@ -110,7 +110,7 @@ def register(smap, missing=None, order=3, method="scipy"):
     return newmap
 
 
-def correct_degradation(smap, correction_table=None, calibration_version=None):
+def correct_degradation(smap, *, correction_table=None, calibration_version=None):
     """
     Apply time-dependent degradation correction to an AIA map.
 
@@ -158,6 +158,7 @@ def correct_degradation(smap, correction_table=None, calibration_version=None):
 def degradation(
     channel: u.angstrom,
     obstime,
+    *,
     correction_table=None,
     calibration_version=None,
 ) -> u.dimensionless_unscaled:
diff --git a/aiapy/calibrate/spikes.py b/aiapy/calibrate/spikes.py
index 63999c4..1ee40f6 100644
--- a/aiapy/calibrate/spikes.py
+++ b/aiapy/calibrate/spikes.py
@@ -14,7 +14,7 @@
 __all__ = ["respike", "fetch_spikes"]
 
 
-def respike(smap, spikes=None):
+def respike(smap, *, spikes=None):
     """
     Re-insert "spikes" or "hot pixels" into level 1 AIA images.
 
diff --git a/aiapy/calibrate/tests/test_prep.py b/aiapy/calibrate/tests/test_prep.py
index fba94ed..297eacb 100644
--- a/aiapy/calibrate/tests/test_prep.py
+++ b/aiapy/calibrate/tests/test_prep.py
@@ -103,7 +103,7 @@ def test_register_level_15(lvl_15_map):
     [
         pytest.param(None, None, marks=pytest.mark.remote_data),
         (
-            get_correction_table(get_test_filepath("aia_V8_20171210_050627_response_table.txt")),
+            get_correction_table(correction_table=get_test_filepath("aia_V8_20171210_050627_response_table.txt")),
             8,
         ),
     ],
diff --git a/aiapy/calibrate/util.py b/aiapy/calibrate/util.py
index 17a1266..aed96e8 100644
--- a/aiapy/calibrate/util.py
+++ b/aiapy/calibrate/util.py
@@ -42,7 +42,7 @@
 }
 
 
-def get_correction_table(correction_table=None):
+def get_correction_table(*, correction_table=None):
     """
     Return table of degradation correction factors.
 
@@ -110,7 +110,7 @@ def get_correction_table(correction_table=None):
 
 @u.quantity_input
 @validate_channel("channel")
-def _select_epoch_from_correction_table(channel: u.angstrom, obstime, table, version=None):
+def _select_epoch_from_correction_table(channel: u.angstrom, obstime, table, *, version=None):
     """
     Return correction table with only the first epoch and the epoch in which
     `obstime` falls and for only one given calibration version.
diff --git a/aiapy/response/channel.py b/aiapy/response/channel.py
index 29d2150..2aced04 100644
--- a/aiapy/response/channel.py
+++ b/aiapy/response/channel.py
@@ -74,7 +74,7 @@ class Channel:
 
     @u.quantity_input
     @validate_channel("channel")
-    def __init__(self, channel: u.angstrom, instrument_file=None):
+    def __init__(self, channel: u.angstrom, *, instrument_file=None):
         self._channel = channel
         self._instrument_data = self._get_instrument_data(instrument_file)
 
diff --git a/aiapy/response/tests/test_channel.py b/aiapy/response/tests/test_channel.py
index f0183c8..f533c5b 100644
--- a/aiapy/response/tests/test_channel.py
+++ b/aiapy/response/tests/test_channel.py
@@ -129,7 +129,7 @@ def test_effective_area(channel):
             1.0140386988603103 * u.dimensionless_unscaled,
         ),
         (
-            get_correction_table(get_test_filepath("aia_V8_20171210_050627_response_table.txt")),
+            get_correction_table(correction_table=get_test_filepath("aia_V8_20171210_050627_response_table.txt")),
             8,
             1.0140386988603103 * u.dimensionless_unscaled,
         ),
diff --git a/aiapy/util/decorators.py b/aiapy/util/decorators.py
index 26312ff..8a09246 100644
--- a/aiapy/util/decorators.py
+++ b/aiapy/util/decorators.py
@@ -17,7 +17,7 @@
 ]
 
 
-def validate_channel(argument, valid_channels="all"):
+def validate_channel(argument, *, valid_channels="all"):
     """
     Parameters
     ----------
diff --git a/pyproject.toml b/pyproject.toml
index a68177e..c2312a6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -70,6 +70,8 @@ docs = [
     "sphinx-hoverxref",
     "sphinxext-opengraph",
     "sunpy-sphinx-theme",
+    # Remove next line when fixed in towncrier; see https://github.com/twisted/towncrier/issues/528
+    "importlib-resources<6",
 ]
 dev = ["aiapy[all,tests,docs]"]