diff --git a/python_tools/void_python_tools/apTools/profiles/getSurveyProps.py b/python_tools/void_python_tools/apTools/profiles/getSurveyProps.py
index c4fcb35..f707e09 100644
--- a/python_tools/void_python_tools/apTools/profiles/getSurveyProps.py
+++ b/python_tools/void_python_tools/apTools/profiles/getSurveyProps.py
@@ -20,16 +20,24 @@
 import numpy as np
 import healpy as healpy
 import scipy.integrate
+import void_python_tools as ct
 
 __all__=['getSurveyProps']
    
 # returns the volume and galaxy density for a given redshit slice
-def getSurveyProps(maskFile, zmin, zmax, selFunMin, selFunMax, portion, selectionFuncFile=None):
+def getSurveyProps(maskFile, zmin, zmax, selFunMin, selFunMax, portion, selectionFuncFile=None, useLCDM=False):
+
+  LIGHT_SPEED = 299792.458
 
   mask = healpy.read_map(maskFile)
   area = (1.*np.size(np.where(mask > 0)) / np.size(mask)) * 4.*np.pi
-  zmin = zmin * 3000
-  zmax = zmax * 3000
+
+  if useLCDM:
+    zmin = LIGHT_SPEED/100.*ct.angularDiameter(zmin, Om=0.27)
+    zmax = LIGHT_SPEED/100.*ct.angularDiameter(zmax, Om=0.27)
+  else:
+    zmin = zmin * 3000
+    zmax = zmax * 3000
   volume = area * (zmax**3  - zmin**3) / 3
 
   if selectionFuncFile != None:
diff --git a/python_tools/void_python_tools/backend/classes.py b/python_tools/void_python_tools/backend/classes.py
index 72701bd..43fee14 100644
--- a/python_tools/void_python_tools/backend/classes.py
+++ b/python_tools/void_python_tools/backend/classes.py
@@ -76,6 +76,7 @@ class Sample:
   includeInHubble = True
   partOfCombo  = False
   isCombo = False
+  useLCDM = False # if True, convert population to comoving coordinates
   comboList = []
 
   # applies to simulations only
@@ -96,6 +97,7 @@ class Sample:
                comboList=(), profileBinSize=2.0, skyFraction=0.19,
                boxLen=1024, usePecVel=False, omegaM=0.27, 
                numSubvolumes=1, mySubvolume=1, dataFormat="sdss",
+               useLCDM=False,
                dataType="observation",
                subsample=1.0, useLightCone=True):
     self.dataFile = dataFile
@@ -126,6 +128,7 @@ class Sample:
     self.subsample = subsample
     self.useLightCone = useLightCone
     self.dataUnit = dataUnit
+    self.useLCDM = useLCDM
 
     self.stacks = []
 
diff --git a/python_tools/void_python_tools/backend/launchers.py b/python_tools/void_python_tools/backend/launchers.py
index de7e6ee..b5e6a83 100644
--- a/python_tools/void_python_tools/backend/launchers.py
+++ b/python_tools/void_python_tools/backend/launchers.py
@@ -330,7 +330,7 @@ def launchPrune(sample, binPath,
   periodicLine = " --periodic='" + getPeriodic(sample) + "'"
 
   if useLCDM:
-    useLCDMFlag = "--useLCDM"
+    useLCDMFlag = " --useLCDM"
   else:
     useLCDMFlag = ""