diff --git a/src/kmmrcore.f b/src/kmmrcore.f
index a9f844e..ff4d6c6 100644
--- a/src/kmmrcore.f
+++ b/src/kmmrcore.f
@@ -6,7 +6,7 @@
 
        subroutine kmmrcore(x,y,txy,n,s,ns,ks,hs,kmmr)
 
-       implicit double precision (a-h,o-z)
+       implicit real*8(a-h,o-z)
 
        integer i,j,iu,n,ns,ks
        double precision wij,vij,hs,kerns,krm,krn,kmmr,x,y,txy
@@ -26,7 +26,7 @@ subroutine kmmrcore(x,y,txy,n,s,ns,ks,hs,kmmr)
           do j=1,n
            if (j.ne.i) then
             hij=sqrt(((xi-x(j))**two)+((yi-y(j))**two))
-            mij=abs(ti*txy(j))
+            mij=ti*txy(j)
               if (ks(1).eq.1) then
                kerns=boxkernel((s(iu)-hij)/hs,hs)
                 else if (ks(2).eq.1) then