diff --git a/CHANGES.rst b/CHANGES.rst
index 1c4483a4..5adb463e 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,10 @@
+0.6.2 (unreleased)
+------------------
+
+- strip None factor for spectral_density in equivalency converter
+  to avoid deprecation warnings for astropy 7. [#229]
+
+
 0.6.1 (2024-04-05)
 ------------------
 
diff --git a/asdf_astropy/converters/unit/equivalency.py b/asdf_astropy/converters/unit/equivalency.py
index 67e273c3..2a889a15 100644
--- a/asdf_astropy/converters/unit/equivalency.py
+++ b/asdf_astropy/converters/unit/equivalency.py
@@ -21,6 +21,9 @@ def from_yaml_tree(self, node, tag, ctx):
             equivalency_method = with_H0 if name == "with_H0" else getattr(equivalencies, name)
 
             kwargs = dict(zip(equivalency_node["kwargs_names"], equivalency_node["kwargs_values"]))
+            # astropy 7.0 deprecated factor, if it's None, don't provide it to spectral_density
+            if "factor" in kwargs and name == "spectral_density" and kwargs["factor"] is None:
+                del kwargs["factor"]
             components.append(equivalency_method(**kwargs))
 
         # The Equivalency class is a UserList that overrides __add__ to
diff --git a/asdf_astropy/converters/unit/tests/test_equivalency.py b/asdf_astropy/converters/unit/tests/test_equivalency.py
index 83d16034..4e3b0bcc 100644
--- a/asdf_astropy/converters/unit/tests/test_equivalency.py
+++ b/asdf_astropy/converters/unit/tests/test_equivalency.py
@@ -12,7 +12,6 @@ def create_equivalencies():
     result = [
         eq.plate_scale(0.3 * u.deg / u.mm),
         eq.pixel_scale(0.5 * u.deg / u.pix),
-        eq.spectral_density(350 * u.nm, factor=2),
         eq.spectral_density(350 * u.nm),
         eq.spectral(),
         eq.brightness_temperature(500 * u.GHz),
@@ -39,6 +38,10 @@ def create_equivalencies():
     if Version(astropy.__version__) >= Version("4.1"):
         result.append(eq.pixel_scale(100.0 * u.pix / u.cm))
 
+    # the factor argument to spectral density is deprecated in astropy 7
+    # skip this test to avoid test failures due to the deprecation warning
+    if Version(astropy.__version__) < Version("7.0.0.dev"):
+        result.append(eq.spectral_density(350 * u.nm, factor=2))
     return result