diff --git a/changes/8966.general.rst b/changes/8966.general.rst
new file mode 100644
index 0000000000..5b21ca6897
--- /dev/null
+++ b/changes/8966.general.rst
@@ -0,0 +1 @@
+Increase asdf upper pin to 5
diff --git a/pyproject.toml b/pyproject.toml
index 26d333cffd..6d61c69b5c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
 ]
 dependencies = [
-    "asdf>=3.1.0,<4",
+    "asdf>=3.1.0,<5",
     "astropy>=5.3",
     "BayesicFitting>=3.0.1",
     "crds>=12.0.3",