diff --git a/configure.ac b/configure.ac
index ed4aaa20da..9a5db943c7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ AC_PREREQ([2.60])
 define(_CLIENT_VERSION_MAJOR, 0)
 define(_CLIENT_VERSION_MINOR, 14)
 define(_CLIENT_VERSION_REVISION, 9)
-define(_CLIENT_VERSION_BUILD, 0)
+define(_CLIENT_VERSION_BUILD, 1)
 define(_CLIENT_VERSION_IS_RELEASE, true)
 define(_COPYRIGHT_YEAR, 2021)
 define(_COPYRIGHT_HOLDERS,[The %s developers])
diff --git a/src/clientversion.h b/src/clientversion.h
index 7f54050f53..26097705d9 100644
--- a/src/clientversion.h
+++ b/src/clientversion.h
@@ -17,7 +17,7 @@
 #define CLIENT_VERSION_MAJOR 0
 #define CLIENT_VERSION_MINOR 14
 #define CLIENT_VERSION_REVISION 9
-#define CLIENT_VERSION_BUILD 0
+#define CLIENT_VERSION_BUILD 1
 
 //! Set to true for release, false for prerelease or test build
 #define CLIENT_VERSION_IS_RELEASE true
diff --git a/src/validation.cpp b/src/validation.cpp
index 9fc2d7c01b..18e0ea96a9 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -4233,6 +4233,11 @@ bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, const
         uint256 final_hash;
         if (block.IsProgPow())
         {
+            // if nHeight is too big progpow_hash_full will use too much memory. This condition allows
+            // progpow usage until block 2600000
+            if (block.nHeight >= progpow::epoch_length*2000)
+                return state.DoS(50, false, REJECT_INVALID, "invalid-progpow-epoch", false, "invalid epoch number");
+
             uint256 exp_mix_hash;
             final_hash = block.GetProgPowHashFull(exp_mix_hash);
             if (exp_mix_hash != block.mix_hash)