diff --git a/bench_nd.py b/bench_nd.py
index d36a59cb5ca9e4bcaab158140eaa5938f6b69943..f532b0e207307034dbee59e81dee6a2f0fb03b9b 100644
--- a/bench_nd.py
+++ b/bench_nd.py
@@ -5,6 +5,7 @@ import pypocketfft
 from time import time
 import matplotlib.pyplot as plt
 
+nthreads=0
 def _l2error(a,b):
     return np.sqrt(np.sum(np.abs(a-b)**2)/np.sum(np.abs(a)**2))
 
@@ -22,7 +23,7 @@ def bench_nd_fftn(ndim, nmax, ntry, tp, nrepeat, filename=""):
         tmin_pp=1e38
         for i in range(nrepeat):
             t0=time()
-            b=pypocketfft.fftn(a)
+            b=pypocketfft.fftn(a,nthreads=nthreads)
             t1=time()
             tmin_pp = min(tmin_pp,t1-t0)
         a2=pypocketfft.ifftn(b,fct=1./a.size)
diff --git a/stress.py b/stress.py
index b347dd95f5753ff3e3c6382884f19ff76b5c4683..422c4a45ba1265af42e9e335ae07b563049c11cc 100644
--- a/stress.py
+++ b/stress.py
@@ -4,7 +4,7 @@ import pypocketfft
 def _l2error(a,b):
     return np.sqrt(np.sum(np.abs(a-b)**2)/np.sum(np.abs(a)**2))
 
-
+nthreads=0
 cmaxerr=0.
 fmaxerr=0.
 cmaxerrf=0.
@@ -23,32 +23,32 @@ def test():
     lastsize = shape[axes[-1]]
     fct = 1./np.prod(np.take(shape, axes))
     a=np.random.rand(*shape)-0.5 + 1j*np.random.rand(*shape)-0.5j
-    b=pypocketfft.ifftn(pypocketfft.fftn(a,axes=axes),axes=axes,fct=fct)
+    b=pypocketfft.ifftn(pypocketfft.fftn(a,axes=axes,nthreads=nthreads),axes=axes,fct=fct,nthreads=nthreads)
     err = _l2error(a,b)
     if err > cmaxerr:
         cmaxerr = err
         print("cmaxerr:", cmaxerr, shape, axes)
-    b=pypocketfft.irfftn(pypocketfft.rfftn(a.real,axes=axes),axes=axes,fct=fct,lastsize=lastsize)
+    b=pypocketfft.irfftn(pypocketfft.rfftn(a.real,axes=axes,nthreads=nthreads),axes=axes,fct=fct,lastsize=lastsize,nthreads=nthreads)
     err = _l2error(a.real,b)
     if err > fmaxerr:
         fmaxerr = err
         print("fmaxerr:", fmaxerr, shape, axes)
-    b=pypocketfft.ifftn(pypocketfft.fftn(a.astype(np.complex64),axes=axes),axes=axes,fct=fct)
+    b=pypocketfft.ifftn(pypocketfft.fftn(a.astype(np.complex64),axes=axes,nthreads=nthreads),axes=axes,fct=fct,nthreads=nthreads)
     err = _l2error(a.astype(np.complex64),b)
     if err > cmaxerrf:
         cmaxerrf = err
         print("cmaxerrf:", cmaxerrf, shape, axes)
-    b=pypocketfft.irfftn(pypocketfft.rfftn(a.real.astype(np.float32),axes=axes),axes=axes,fct=fct,lastsize=lastsize)
+    b=pypocketfft.irfftn(pypocketfft.rfftn(a.real.astype(np.float32),axes=axes,nthreads=nthreads),axes=axes,fct=fct,lastsize=lastsize,nthreads=nthreads)
     err = _l2error(a.real.astype(np.float32),b)
     if err > fmaxerrf:
         fmaxerrf = err
         print("fmaxerrf:", fmaxerrf, shape, axes)
-    b=pypocketfft.hartley(pypocketfft.hartley(a.real,axes=axes),axes=axes,fct=fct)
+    b=pypocketfft.hartley(pypocketfft.hartley(a.real,axes=axes,nthreads=nthreads),axes=axes,fct=fct,nthreads=nthreads)
     err = _l2error(a.real,b)
     if err > hmaxerr:
         hmaxerr = err
         print("hmaxerr:", hmaxerr, shape, axes)
-    b=pypocketfft.hartley(pypocketfft.hartley(a.real.astype(np.float32),axes=axes),axes=axes,fct=fct)
+    b=pypocketfft.hartley(pypocketfft.hartley(a.real.astype(np.float32),axes=axes,nthreads=nthreads),axes=axes,fct=fct,nthreads=nthreads)
     err = _l2error(a.real.astype(np.float32),b)
     if err > hmaxerrf:
         hmaxerrf = err