1 files changed, 5 insertions, 1 deletions
diff --git a/src/chain.h b/src/chain.h
index 55bdf4cd56..534f226f28 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -10,6 +10,7 @@
 #include <consensus/params.h>
 #include <flatfile.h>
 #include <primitives/block.h>
+#include <sync.h>
 #include <tinyformat.h>
 #include <uint256.h>
 
@@ -37,6 +38,8 @@ static constexpr int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
  */
 static constexpr int64_t MAX_BLOCK_TIME_GAP = 90 * 60;
 
+extern RecursiveMutex cs_main;
+
 class CBlockFileInfo
 {
 public:
@@ -223,8 +226,9 @@ public:
     {
     }
 
-    FlatFilePos GetBlockPos() const
+    FlatFilePos GetBlockPos() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {
+        AssertLockHeld(::cs_main);
         FlatFilePos ret;
         if (nStatus & BLOCK_HAVE_DATA) {
             ret.nFile = nFile;