diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4d56a65..2199a20 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## Next version
+
+### ✨ Improved
+
+- Added `ISFSWEEP` header keywords to `PROC` extension.
+
+
 ## 0.4.11 - February 4, 2024
 
 ### ✨ Improved
diff --git a/python/lvmcam/models/proc.py b/python/lvmcam/models/proc.py
index efaf2b4..86e4844 100644
--- a/python/lvmcam/models/proc.py
+++ b/python/lvmcam/models/proc.py
@@ -79,6 +79,11 @@
             value=None,
             comment="Reference file for astrometric solution",
         ),
+        Card(
+            "ISFSWEEP",
+            value=False,
+            comment="Is the exposure part of a focus sweep?",
+        ),
         Card(
             "SOLVED",
             value=False,