diff --git a/lib/qra/q65/q65_loops.f90 b/lib/qra/q65/q65_loops.f90
index a1bcc64cb..f6a80a2a9 100644
--- a/lib/qra/q65/q65_loops.f90
+++ b/lib/qra/q65/q65_loops.f90
@@ -59,7 +59,8 @@ subroutine q65_loops(c00,npts2,nsps2,nsubmode,ndepth,jpk0,    &
         ndt=idt/2
         if(mod(idt,2).eq.0) ndt=-ndt
         jpk=jpk0 + nsps2*ndt/16              !tsym/16
-        if(jpk.lt.0) jpk=0
+        jpk=max(0,jpk)
+        jpk=min(29000,jpk)
         call spec64(c0,nsps2,mode_q65,jpk,s3,LL,NN)
         call pctile(s3,LL*NN,40,base)
         s3=s3/base