diff --git a/docs/CHANGELOG.asciidoc b/docs/CHANGELOG.asciidoc
index 9c35475f60..823e3f0708 100644
--- a/docs/CHANGELOG.asciidoc
+++ b/docs/CHANGELOG.asciidoc
@@ -33,6 +33,7 @@
 === Bug Fixes
 
 * Correct inference model definition for MSLE regression models. (See {ml-pull}1375[#1375].)
+* Fix restoration of change detectors after seasonality change. (See {ml-pull}1391[#1391].)
 * Fix cause of SIGSEGV of classification and regression. (See {ml-pull}1379[#1379].)
 
 == {es} version 7.8.1
diff --git a/include/maths/CTimeSeriesChangeDetector.h b/include/maths/CTimeSeriesChangeDetector.h
index 5e3b9f1429..eb0aa2134b 100644
--- a/include/maths/CTimeSeriesChangeDetector.h
+++ b/include/maths/CTimeSeriesChangeDetector.h
@@ -136,6 +136,9 @@ class MATHS_EXPORT CUnivariateTimeSeriesChangeDetector {
     using TMinMaxAccumulator = CBasicStatistics::CMinMax<core_t::TTime>;
     using TRegression = CLeastSquaresOnlineRegression<1, double>;
 
+    //! Initialise the m_ChangeModels vector
+    void initChangeModels(TPriorPtr residualModel);
+
 private:
     //! The minimum amount of time we need to observe before
     //! selecting a change model.
@@ -227,6 +230,9 @@ class MATHS_EXPORT CUnivariateChangeModel {
     //! Get a checksum for this object.
     virtual uint64_t checksum(uint64_t seed) const = 0;
 
+    //! Get the time series residual model member variable.
+    const TPriorPtr& residualModelPtr() const;
+
 protected:
     CUnivariateChangeModel(const CUnivariateChangeModel& other,
                            const TDecompositionPtr& trendModel,
@@ -257,8 +263,6 @@ class MATHS_EXPORT CUnivariateChangeModel {
     const CPrior& residualModel() const;
     //! Get the time series residual model.
     CPrior& residualModel();
-    //! Get the time series residual model member variable.
-    const TPriorPtr& residualModelPtr() const;
 
 private:
     using TMeanVarAccumulator = CBasicStatistics::SSampleMeanVar<double>::TAccumulator;
diff --git a/lib/maths/CTimeSeriesChangeDetector.cc b/lib/maths/CTimeSeriesChangeDetector.cc
index 19c5e74bb8..797865af5b 100644
--- a/lib/maths/CTimeSeriesChangeDetector.cc
+++ b/lib/maths/CTimeSeriesChangeDetector.cc
@@ -98,11 +98,16 @@ CUnivariateTimeSeriesChangeDetector::CUnivariateTimeSeriesChangeDetector(
     : m_MinimumTimeToDetect{minimumTimeToDetect}, m_MaximumTimeToDetect{maximumTimeToDetect},
       m_MinimumDeltaBicToDetect{minimumDeltaBicToDetect}, m_SampleCount{0},
       m_DecisionFunction{0.0}, m_TrendModel{trendModel->clone()} {
+    this->initChangeModels(residualModel);
+}
+
+void CUnivariateTimeSeriesChangeDetector::initChangeModels(TPriorPtr residualModel) {
+    m_ChangeModels.clear();
     m_ChangeModels.push_back(
-        std::make_unique<CUnivariateNoChangeModel>(trendModel, residualModel));
+        std::make_unique<CUnivariateNoChangeModel>(m_TrendModel, residualModel));
     m_ChangeModels.push_back(
         std::make_unique<CUnivariateLevelShiftModel>(m_TrendModel, residualModel));
-    if (trendModel->seasonalComponents().size() > 0) {
+    if (m_TrendModel->seasonalComponents().size() > 0) {
         m_ChangeModels.push_back(std::make_unique<CUnivariateTimeShiftModel>(
             m_TrendModel, residualModel, -core::constants::HOUR));
         m_ChangeModels.push_back(std::make_unique<CUnivariateTimeShiftModel>(
@@ -146,10 +151,13 @@ bool CUnivariateTimeSeriesChangeDetector::acceptRestoreTraverser(
         RESTORE_SETUP_TEARDOWN(MAX_TIME_TAG, core_t::TTime time,
                                core::CStringUtils::stringToType(traverser.value(), time),
                                m_TimeRange.add(time))
-        RESTORE(TREND_MODEL_TAG, traverser.traverseSubLevel(std::bind<bool>(
-                                     CTimeSeriesDecompositionStateSerialiser(),
-                                     std::cref(params.s_DecompositionParams),
-                                     std::ref(m_TrendModel), std::placeholders::_1)))
+        RESTORE_SETUP_TEARDOWN(TREND_MODEL_TAG, /**/,
+                               traverser.traverseSubLevel(std::bind<bool>(
+                                   CTimeSeriesDecompositionStateSerialiser(),
+                                   std::cref(params.s_DecompositionParams),
+                                   std::ref(m_TrendModel), std::placeholders::_1)),
+                               this->initChangeModels((*model)->residualModelPtr());
+                               model = m_ChangeModels.begin())
         RESTORE_SETUP_TEARDOWN(
             CHANGE_MODEL_TAG, TChangeModelPtr restoredModel{(*model)->clone(m_TrendModel)},
             traverser.traverseSubLevel(std::bind(