diff --git a/xray/azav.py b/xray/azav.py
index fa4daaa..9090d27 100644
--- a/xray/azav.py
+++ b/xray/azav.py
@@ -218,7 +218,7 @@ def removeBackground(data,qlims=(0,10),max_iter=30,background_regions=[],force=F
   return data
 
 
-def doFolder(folder,files='*.edf*',nQ = 1500,force=False,mask=None,dark=10,norm='auto',
+def doFolder(folder,files='*.edf*',nQ = 1500,force=False,mask=None,dark=10,norm='auto',save_pyfai=False,
              saveChi=True,poni='pyfai.poni',storageFile='auto',save=True,diagnostic=None,skip_first=0,last=None):
   """ calc 1D curves from files in folder, returning a dictionary of stuff
       nQ    : number of Q-points (equispaced)
@@ -227,6 +227,7 @@ def doFolder(folder,files='*.edf*',nQ = 1500,force=False,mask=None,dark=10,norm=
       mask  : can be a list of [filenames|array of booleans|mask string]
               pixels that are True are dis-regarded
       saveChi: self-explanatory
+      save_pyfai: save all pyfai's internal arrays (~110 MB)
       poni  : could be:
               → an AzimuthalIntegrator instance
               → a filename that will be look for in
@@ -285,6 +286,7 @@ def doFolder(folder,files='*.edf*',nQ = 1500,force=False,mask=None,dark=10,norm=
     ret = dict(q=q,folder=folder,files=files,data=data,err=err,
           data_orig=data.copy(),err_orig=err.copy(),q_orig=q.copy(),
           pyfai=ai_as_dict(ai),pyfai_info=ai_as_str(ai),mask=mask)
+    if not save_pyfai: del ret['pyfai']
 
     # add info from diagnostic if provided
     if diagnostic is not None: