diff --git a/docs/CHANGELOG.asciidoc b/docs/CHANGELOG.asciidoc
index b6122770b4..7c8d4f2cec 100644
--- a/docs/CHANGELOG.asciidoc
+++ b/docs/CHANGELOG.asciidoc
@@ -52,6 +52,7 @@
 * Avoid potential "Failed to compute quantile" and "No values added to quantile sketch" log errors
   training regression and classification models if there are features with mostly missing values.
   (See {ml-pull}1500[#1500].)
+* Correct the anomaly detection job model state `min_version`. (See {ml-pull}1546[#1546].)
 
 == {es} version 7.9.2
 
diff --git a/lib/api/CAnomalyJob.cc b/lib/api/CAnomalyJob.cc
index 2f7e51d621..6a4ecc37a4 100644
--- a/lib/api/CAnomalyJob.cc
+++ b/lib/api/CAnomalyJob.cc
@@ -85,7 +85,12 @@ const std::string INTERIM_BUCKET_CORRECTOR_TAG("k");
 
 //! The minimum version required to read the state corresponding to a model snapshot.
 //! This should be updated every time there is a breaking change to the model state.
-const std::string MODEL_SNAPSHOT_MIN_VERSION("6.4.0");
+//! Newer versions are able to read the model state of older versions, but older
+//! versions cannot read the model state of newer versions following a breaking
+//! change.  This constant tells the node assignment code not to load new model states
+//! on old nodes in a mixed version cluster.  (The last breaking change was in 7.9 in
+//! lib/core/CPackedBitVector.cc in https://github.com/elastic/ml-cpp/pull/1340.)
+const std::string MODEL_SNAPSHOT_MIN_VERSION("7.9.0");
 
 //! Persist state as JSON with meaningful tag names.
 class CReadableJsonStatePersistInserter : public core::CJsonStatePersistInserter {