diff --git a/enrico/fitmaker.py b/enrico/fitmaker.py
index f86f584..59a7b88 100755
--- a/enrico/fitmaker.py
+++ b/enrico/fitmaker.py
@@ -19,7 +19,7 @@
 
 class FitMaker(Loggin.Message):
     """Collection of functions to prepare/run the GTLIKE fit
-     and compute an upper limit is needed"""
+     and compute an upper limit if needed"""
     def __init__(self, obs, config):
         super(FitMaker,self).__init__()
         Loggin.Message.__init__(self)
@@ -42,7 +42,7 @@ def GenerateFits(self):
         """Run the different ST tools and compute the fits files
            First it runs the tools that are common to the binned 
            and unbinned analysis chain then it run the specific
-           tools following the choise of the user"""
+           tools following the choice of the user"""
 
         #Run the tools common to binned and unbinned chain
         self._log('gtselect', 'Select data from library')#run gtselect
@@ -54,8 +54,19 @@ def GenerateFits(self):
             self.obs.DiffResps()#run gtdiffresp
         self._log('gtbin', 'Create a count map')
         self.obs.Gtbin()
-        self._log('gtltcube', 'Make live time cube')#run gtexpcube
-        self.obs.ExpCube()
+        # Produces ltcube depending on whether the variable below is empty
+        # otherwise uses the one provided in the string (i.e. gtltcube
+        # will not even be called)
+        if self.config['file']['ltcube'] == "": 
+            self._log('gtltcube', 'Make live time cube')#run gtexpcube
+            self.obs.ExpCube()
+        else:
+            self._log('gtltcube', 'Make live time cube')
+            print "Skipping creation of live time cube: it was generated before"
+            print self.config['file']['ltcube']
+
+
+        	
 
         #Choose between the binned of the unbinned analysis
         if self.config['analysis']['likelihood'] == 'binned': #binned analysis chain
diff --git a/enrico/gtfunction.py b/enrico/gtfunction.py
index 11dc06d..deece59 100755
--- a/enrico/gtfunction.py
+++ b/enrico/gtfunction.py
@@ -15,11 +15,11 @@
 class Observation:
     # init function of the Observation class. 
     # folder : folder where the produced fits files will be stored.
-    # configuration is the confi of enrico (contains the variable)
+    # configuration is the config of enrico (contains the variables)
     
     def __init__(self,folder,Configuration,tag=""):
         
-        #Read the configuration object and init all the variable
+        #Read the configuration object and init all variables
         self.Configuration = Configuration
         inttag = "_"+Configuration['file']['tag']
         if not(tag==""):
@@ -32,7 +32,11 @@ def __init__(self,folder,Configuration,tag=""):
 
         #Fits files
         self.eventfile = folder+'/'+self.srcname+inttag+"_Evt.fits"
-        self.Cubename  = folder+'/'+self.srcname+inttag+"_ltCube.fits"
+        if Configuration['file']['ltcube'] == "":
+           self.Cubename  = folder+'/'+self.srcname+inttag+"_ltCube.fits"
+        else:
+           self.Cubename  = Configuration['file']['ltcube']
+                  
         self.Mapname   = folder+'/'+self.srcname+inttag+"_ExpMap.fits"
         self.BinnedMapfile = folder+'/'+self.srcname+inttag+"_BinnedMap.fits"
         self.cmapfile  = folder+'/'+self.srcname+inttag+"_CountMap.fits"
@@ -279,7 +283,7 @@ def ExpCube(self):
         expCube['zmax']=self.Configuration['analysis']['zmax'] 
         expCube['phibins']=self.Configuration['space']['phibins']
         expCube['clobber'] = self.clobber
-        expCube.run()
+       	expCube.run()
 
     def ExpMap(self):
         "Run gtexpmap for unbinned analysis"