diff --git a/src/pybdsim/Beam.py b/src/pybdsim/Beam.py
index 7010bdd..538de2f 100644
--- a/src/pybdsim/Beam.py
+++ b/src/pybdsim/Beam.py
@@ -111,7 +111,7 @@ def _MakeGaussTwiss(self):
         setattr(self, 'SetDispYP',     self._SetDispYP)
 
     def SetDistributionType(self,distrType='reference'):
-        if distrType not in BDSIMDistributionTypes:
+        if distrType not in BDSIMDistributionTypes and not 'bdsimsampler:' in distrType and not 'eventgeneratorfile:' in distrType:
             raise ValueError("Unknown distribution type: '"+str(distrType)+"'")
         self['distrType'] = '"' + distrType + '"'
         self._UpdateMemberFunctions(distrType)
diff --git a/src/pybdsim/Builder.py b/src/pybdsim/Builder.py
index fb61e3a..93d786c 100644
--- a/src/pybdsim/Builder.py
+++ b/src/pybdsim/Builder.py
@@ -1325,14 +1325,15 @@ def Insert(self, newElement, index = 0, after = False, substitute = False):
             if newElement.name in self.elements.keys():
                 if not substitute:
                     raise ValueError(f"New element {newElement.name} already exists in elements. If you want to overwrite it, set substitute=True")
-            else:
-                self.elements[newElement.name] = newElement
+            self.elements[newElement.name] = newElement
+            
+            # Modify sequence
+            self.sequence.insert(index, newElement.name)
         elif isinstance(newElement, str):
             if newElement not in self.elements.keys():
                 raise ValueError(f"New element {newElement} not found in elements")
-
-        # Modify sequence
-        self.sequence.insert(index, newElement.name)
+            # Modify sequence
+            self.sequence.insert(index, newElement)
 
     def InsertAndReplace(self, newElement, sLocation = 0, element_name = None):
         """
diff --git a/tests/test_builder.py b/tests/test_builder.py
index 9d8a2e9..1104012 100644
--- a/tests/test_builder.py
+++ b/tests/test_builder.py
@@ -257,6 +257,31 @@ def test_Laser_repr():
     expected = 'myl: laser, l=0.1, waveLength=5370, x=0.2, y=0.3, z=0.4;\n'
     assert repr(laser) == expected
 
+def test_Insert():
+    machine = pybdsim.Builder.Machine()
+    machine.AddDrift(name="dr", length=0.1)
+    machine.Insert(pybdsim.Builder.RBend("myr", 0.1, angle=0), index = "dr")
+    machine.Insert(pybdsim.Builder.RBend("myr1", 0.1, angle=0), index = "dr", after=True)
+    machine.Insert("dr", index = "myr1", after=True, substitute=True)
+    expected = ['myr', 'dr', 'myr1', 'dr']
+    assert machine.sequence == expected
+
+def test_bdsimsampler_repr():
+    beam = pybdsim.Beam.Beam()
+    beam.SetDistributionType("bdsimsampler:SAMPLER")
+    beam.SetEnergy(100)
+    beam.SetParticleType("proton")
+    expected = 'beam,\tdistrType="bdsimsampler:SAMPLER",\n\tenergy=100*GeV, \n\tparticle="proton";'
+    assert repr(beam) == expected
+
+def test_eventgeneratorfile_repr():
+    beam = pybdsim.Beam.Beam()
+    beam.SetDistributionType("eventgeneratorfile:FORMAT")
+    beam.SetEnergy(100)
+    beam.SetParticleType("proton")
+    expected = 'beam,\tdistrType="eventgeneratorfile:FORMAT",\n\tenergy=100*GeV, \n\tparticle="proton";'
+    assert repr(beam) == expected
+
 #def test_element_split_drift():
 #    c = pybdsim.Builder.Element('d1', 'drift', l=(0.4, 'm'), aper1=(2, 'cm'))
 #    b = c/2