diff --git a/src/qt/clientmodel.cpp b/src/qt/clientmodel.cpp
index 9a8af01a32dc3..cbc6ca1296f32 100644
--- a/src/qt/clientmodel.cpp
+++ b/src/qt/clientmodel.cpp
@@ -74,7 +74,7 @@ int ClientModel::getNumBlocks() const
     return chainActive.Height();
 }
 
-int ClientModel::getHeaderTipHeight()
+int ClientModel::getHeaderTipHeight() const
 {
     if (cachedBestHeaderHeight == -1) {
         // make sure we initially populate the cache via a cs_main lock
@@ -87,7 +87,7 @@ int ClientModel::getHeaderTipHeight()
     return cachedBestHeaderHeight;
 }
 
-int64_t ClientModel::getHeaderTipTime()
+int64_t ClientModel::getHeaderTipTime() const
 {
     if (cachedBestHeaderTime == -1) {
         LOCK(cs_main);
diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
index 6f7077dad612d..0e6b34fbfd290 100644
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -51,8 +51,8 @@ class ClientModel : public QObject
     //! Return number of connections, default is in- and outbound (total)
     int getNumConnections(unsigned int flags = CONNECTIONS_ALL) const;
     int getNumBlocks() const;
-    int getHeaderTipHeight();
-    int64_t getHeaderTipTime();
+    int getHeaderTipHeight() const;
+    int64_t getHeaderTipTime() const;
     //! Return number of transactions in the mempool
     long getMempoolSize() const;
     //! Return the dynamic memory usage of the mempool
@@ -82,8 +82,8 @@ class ClientModel : public QObject
     QString dataDir() const;
 
     // caches for the best header
-    std::atomic<int> cachedBestHeaderHeight;
-    std::atomic<int64_t> cachedBestHeaderTime;
+    mutable std::atomic<int> cachedBestHeaderHeight;
+    mutable std::atomic<int64_t> cachedBestHeaderTime;
 
 private:
     OptionsModel *optionsModel;