diff --git a/src/pow.cpp b/src/pow.cpp
index de1a7904b..f8c09556e 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -102,11 +102,11 @@ arith_uint256 RT_CST_RST(int32_t height,uint32_t nTime,arith_uint256 bnTarget,ui
     int64_t altK; int32_t i,j,ii=0; // K is a scaling factor for integer divisions
     if ( height < 64 )
         return(bnTarget);
-    if ( ts[0]-ts[W] < T*numerator/denominator )
+    if ( ((ts[0]-ts[W]) * W * 100)/(W-1) < (T * numerator * 100)/denominator )
     {
         //bnTarget = ((ct[0]-ct[1])/K) * max(K,(K*(nTime-ts[0])*(ts[0]-ts[W])*denominator/numerator)/T/T);
         bnTarget = (ct[0] - ct[1]) / arith_uint256(K);
-        altK = (K * (nTime-ts[0]) * (ts[0]-ts[W]) * denominator / numerator) / (T * T);
+        altK = (K * (nTime-ts[0]) * (ts[0]-ts[W]) * denominator * W) / (numerator * (W-1) * (T * T));
         fprintf(stderr,"ht.%d initial altK.%lld %d * %d * %d / %d\n",height,(long long)altK,(nTime-ts[0]),(ts[0]-ts[W]),denominator,numerator);
         if ( altK > K )
             altK = K;
@@ -292,7 +292,7 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
         {
             origtarget = bnTarget;
             // bnTarget = RT_CST_RST (height,nTime,bnTarget, ts, cw, numerator, denominator, W, T, past);
-            bnTarget = RT_CST_RST(height,pblock->nTime,bnTarget,ts,ct,1,2,3,50);
+            bnTarget = RT_CST_RST(height,pblock->nTime,bnTarget,ts,ct,1,2,3,20);
             if ( 0 )
             {
                 bnTarget6 = RT_CST_RST(height,pblock->nTime,bnTarget,ts,ct,7,3,6,50);