diff --git a/openquake/calculators/ucerf_base.py b/openquake/calculators/ucerf_base.py
index <HASH>..<HASH> 100644
--- a/openquake/calculators/ucerf_base.py
+++ b/openquake/calculators/ucerf_base.py
@@ -193,7 +193,7 @@ class UCERFSource(BaseSeismicSource):
         self.mesh_spacing = mesh_spacing
         self.tectonic_region_type = trt
         self.stop = 0
-        self.start = 0
+        self.start = -1
         self.orig = None  # set by .new()
 
     @property
diff --git a/openquake/hazardlib/sourceconverter.py b/openquake/hazardlib/sourceconverter.py
index <HASH>..<HASH> 100644
--- a/openquake/hazardlib/sourceconverter.py
+++ b/openquake/hazardlib/sourceconverter.py
@@ -145,7 +145,10 @@ class SourceGroup(collections.Sequence):
         """
         assert src.tectonic_region_type == self.trt, (
             src.tectonic_region_type, self.trt)
-        self.tot_ruptures += get_set_num_ruptures(src)
+        nr = get_set_num_ruptures(src)
+        if nr == 0:  # the minimum_magnitude filters all ruptures
+            return
+        self.tot_ruptures += nr
         self.sources.append(src)
         min_mag, max_mag = src.get_min_max_mag()
         prev_min_mag = self.min_mag
Fixed filtered out sources [demos]


Former-commit-id: <I>dd<I>ff6a<I>aab<I>f2cf<I>bbed<I>f<I>fc6c