diff --git a/fvnlib.f90 b/fvnlib.f90
index baf1248..e49511b 100644
--- a/fvnlib.f90
+++ b/fvnlib.f90
@@ -2510,21 +2510,25 @@ implicit none
 double precision, external :: f
 double precision, intent(in) :: a,b,epsabs,epsrel
 integer, intent(in) :: key
-integer, intent(in) :: limit
+integer, intent(in),optional :: limit
 double precision, intent(out) :: res,abserr
 integer, intent(out) :: ier
 
 double precision, allocatable :: work(:)
 integer, allocatable :: iwork(:)
 integer :: lenw,neval,last
+integer :: limitw
 
 ! imsl value for limit is 500
-lenw=limit*4
+limitw=500
+if (present(limit)) limitw=limit
 
-allocate(iwork(limit))
+lenw=limitw*4
+
+allocate(iwork(limitw))
 allocate(work(lenw))
 
-call dqag(f,a,b,epsabs,epsrel,key,res,abserr,neval,ier,limit,lenw,last,iwork,work)
+call dqag(f,a,b,epsabs,epsrel,key,res,abserr,neval,ier,limitw,lenw,last,iwork,work)
 
 deallocate(work)
 deallocate(iwork)
@@ -2597,21 +2601,26 @@ subroutine fvn_d_integ_2_gk(f,a,b,g,h,epsabs,epsrel,key,res,abserr,ier,limit)
 implicit none
 double precision, external:: f,g,h
 double precision, intent(in) :: a,b,epsabs,epsrel
-integer, intent(in) :: key,limit
+integer, intent(in) :: key
+integer, intent(in), optional :: limit
 integer, intent(out) :: ier
 double precision, intent(out) :: res,abserr
 
 
 double precision, allocatable :: work(:)
+integer :: limitw
 integer, allocatable :: iwork(:)
 integer :: lenw,neval,last
 
 ! imsl value for limit is 500
-lenw=limit*4
+limitw=500
+if (present(limit)) limitw=limit
+
+lenw=limitw*4
 allocate(work(lenw))
-allocate(iwork(limit))
+allocate(iwork(limitw))
 
-call dqag_2d_outer(f,a,b,g,h,epsabs,epsrel,key,res,abserr,neval,ier,limit,lenw,last,iwork,work)
+call dqag_2d_outer(f,a,b,g,h,epsabs,epsrel,key,res,abserr,neval,ier,limitw,lenw,last,iwork,work)
 
 deallocate(iwork)
 deallocate(work)
@@ -2685,21 +2694,26 @@ subroutine fvn_d_integ_2_inner_gk(f,x,a,b,epsabs,epsrel,key,res,abserr,ier,limit
 implicit none
 double precision, external:: f
 double precision, intent(in) :: x,a,b,epsabs,epsrel
-integer, intent(in) :: key,limit
+integer, intent(in) :: key
+integer, intent(in),optional :: limit
 integer, intent(out) :: ier
 double precision, intent(out) :: res,abserr
 
 
 double precision, allocatable :: work(:)
+integer :: limitw
 integer, allocatable :: iwork(:)
 integer :: lenw,neval,last
 
 ! imsl value for limit is 500
-lenw=limit*4
+limitw=500
+if (present(limit)) limitw=limit
+
+lenw=limitw*4
 allocate(work(lenw))
-allocate(iwork(limit))
+allocate(iwork(limitw))
 
-call dqag_2d_inner(f,x,a,b,epsabs,epsrel,key,res,abserr,neval,ier,limit,lenw,last,iwork,work)
+call dqag_2d_inner(f,x,a,b,epsabs,epsrel,key,res,abserr,neval,ier,limitw,lenw,last,iwork,work)
 
 deallocate(iwork)
 deallocate(work)