diff --git a/pyfstat/core.py b/pyfstat/core.py
index bc2b7761f0bf9763dc444210ebc01657cc88cbd3..9bb8cf603b4d6a41fcb7bd81b06b842433299a6d 100755
--- a/pyfstat/core.py
+++ b/pyfstat/core.py
@@ -1041,9 +1041,9 @@ transientTauDays={:1.3f}\n""")
         if self.add_noise:
             cl.append('--sqrtSX="{}"'.format(self.sqrtSX))
         if self.minStartTime is None:
-            cl.append('--startTime={:10.0f}'.format(float(self.tstart)))
+            cl.append('--startTime={:0.0f}'.format(float(self.tstart)))
         else:
-            cl.append('--startTime={:10.0f}'.format(float(self.minStartTime)))
+            cl.append('--startTime={:0.0f}'.format(float(self.minStartTime)))
         if self.maxStartTime is None:
             cl.append('--duration={}'.format(int(self.duration)))
         else:
diff --git a/tests.py b/tests.py
index 503eaf1b53c1b2704accefd7e8e384855c162733..090d50f50114ecea81e98edbb1eb36952cd7dcce 100644
--- a/tests.py
+++ b/tests.py
@@ -192,7 +192,7 @@ class TestMCMCSearch(Test):
     label = "Test"
 
     def test_fully_coherent(self):
-        h0 = 1e-24
+        h0 = 5e-24
         sqrtSX = 1e-22
         F0 = 30
         F1 = -1e-10
@@ -233,7 +233,7 @@ class TestMCMCSearch(Test):
             FS > predicted_FS or np.abs((FS-predicted_FS))/predicted_FS < 0.3)
 
     def test_multi_stage(self):
-        Writer = pyfstat.Writer()
+        Writer = pyfstat.Writer(F0=10)
         Writer.make_cff()
 
         theta = {'F0': {'type': 'norm', 'loc': 10, 'scale': 1e-2},