diff --git a/lib/downsam9.f90 b/lib/downsam9.f90
index 575ff7d61..9b5ab66ee 100644
--- a/lib/downsam9.f90
+++ b/lib/downsam9.f90
@@ -41,7 +41,9 @@ subroutine downsam9(id2,npts8,nsps8,newdat,nspsd,fpk,c2,nz2)
 ! Plan the FFTs just once
 
      !$omp critical(fftw) ! serialize non thread-safe FFTW3 calls
+     call fftwf_plan_with_nthreads(nthreads)
      plan=fftwf_plan_dft_r2c_1d(nfft1,x1,c1,nflags)
+     call fftwf_plan_with_nthreads(1)
      !$omp end critical(fftw)
 
      first=.false.
diff --git a/lib/filbig.f90 b/lib/filbig.f90
index 26b23c3a8..4c1a687c0 100644
--- a/lib/filbig.f90
+++ b/lib/filbig.f90
@@ -41,7 +41,9 @@ subroutine filbig(dd,npts,f0,newdat,c4a,n4,sq0)
 
 ! Plan the FFTs just once
      !$omp critical(fftw) ! serialize non thread-safe FFTW3 calls
+     call fftwf_plan_with_nthreads(nthreads)
      plan1=fftwf_plan_dft_r2c_1d(nfft1,rca,ca,nflags)
+     call fftwf_plan_with_nthreads(1)
      plan2=fftwf_plan_dft_1d(nfft2,c4a,c4a,-1,nflags)
      plan3=fftwf_plan_dft_1d(nfft2,cfilt,cfilt,+1,nflags)
      !$omp end critical(fftw)
diff --git a/lib/jt9.f90 b/lib/jt9.f90
index 217ec44be..515eaad05 100644
--- a/lib/jt9.f90
+++ b/lib/jt9.f90
@@ -79,7 +79,7 @@ program jt9
   endif
 
   iret=fftwf_init_threads()                   !Initialize FFTW threading 
-  call fftwf_plan_with_nthreads(nthreads)
+  call fftwf_plan_with_nthreads(1)            !Default to 1 thread but use nthreads for the big ones
 ! Import FFTW wisdom, if available
   wisfile=trim(data_dir)//'/jt9_wisdom.dat'// C_NULL_CHAR
   iret=fftwf_import_wisdom_from_filename(wisfile)