diff --git a/pyfstat/core.py b/pyfstat/core.py
index 914022e93782ec46918279dac998020f33bed6c1..6a278675c0345077744c1a2fdf763a4ad942b01e 100755
--- a/pyfstat/core.py
+++ b/pyfstat/core.py
@@ -159,6 +159,8 @@ def predict_fstat(
     IFOs=None,
     assumeSqrtSX=None,
     tempory_filename="fs.tmp",
+    earth_ephem=None,
+    sun_ephem=None,
     **kwargs
 ):
     """ Wrapper to lalapps_PredictFstat
@@ -201,6 +203,11 @@ def predict_fstat(
     cl_pfs.append("--maxStartTime={}".format(int(maxStartTime)))
     cl_pfs.append("--outputFstat={}".format(tempory_filename))
 
+    if earth_ephem is not None:
+        cl_pfs.append("--ephemEarth='{}'".format(earth_ephem))
+    if sun_ephem is not None:
+        cl_pfs.append("--ephemSun='{}'".format(sun_ephem))
+
     cl_pfs = " ".join(cl_pfs)
     helper_functions.run_commandline(cl_pfs)
     d = read_par(filename=tempory_filename)
diff --git a/pyfstat/make_sfts.py b/pyfstat/make_sfts.py
index fdf0d28799679c55bc68a0b22aaa9940ea64e56c..9ad3149d6449c7a924789aa0d4c389c76c3b5988 100644
--- a/pyfstat/make_sfts.py
+++ b/pyfstat/make_sfts.py
@@ -377,6 +377,8 @@ transientTau = {:10.0f}\n"""
             self.detectors,
             self.sqrtSX,
             tempory_filename="{}.tmp".format(self.label),
+            earth_ephem=self.earth_ephem,
+            sun_ephem=self.sun_ephem
         )  # detectors OR IFO?
         return twoF_expected