diff --git a/samples/shallow-mixed/tstep.f90 b/samples/shallow-mixed/tstep.f90
index 9402dfb..2a81dd4 100644
--- a/samples/shallow-mixed/tstep.f90
+++ b/samples/shallow-mixed/tstep.f90
@@ -26,7 +26,6 @@
 
 subroutine tstep(m,n,alpha,jstart,jend,cpold,cuold,cvold,cp,cu,cv,cpnew,cunew,cvnew,cdpdt,cdudt,cdvdt,firststep,tdt) bind(c)
   use, intrinsic :: ISO_C_BINDING
-  implicit none
 
   integer(kind=C_INT), value :: m, n
   real(kind=C_FLOAT), value :: alpha
@@ -46,8 +45,6 @@
   integer(kind=C_INT), value :: firststep
   real(kind=C_FLOAT), value  :: tdt
 
-  integer i,j
-
   call c_f_pointer(cpold, pold, shape=[m, n])
   call c_f_pointer(cuold, uold, shape=[m, n])
   call c_f_pointer(cvold, vold, shape=[m, n])