diff --git a/interfaces/cython/cantera/ck2cti.py b/interfaces/cython/cantera/ck2cti.py
index 93323a737..4c40635a7 100644
--- a/interfaces/cython/cantera/ck2cti.py
+++ b/interfaces/cython/cantera/ck2cti.py
@@ -847,7 +847,12 @@ class TransportData(object):
     def __init__(self, label, geometry, wellDepth, collisionDiameter,
                  dipoleMoment, polarizability, zRot, comment=None):
 
-        if int(geometry) not in (0,1,2):
+        try:
+            geometry = int(geometry)
+        except ValueError:
+            raise InputParseError("Bad geometry flag '{0}' for species '{1}', is the flag a float "
+                                  "or character? It should be an integer.".format(geometry, label))
+        if geometry not in (0, 1, 2):
             raise InputParseError("Bad geometry flag '{0}' for species '{1}'".format(geometry, label))
 
         self.label = label
diff --git a/interfaces/cython/cantera/test/test_convert.py b/interfaces/cython/cantera/test/test_convert.py
index 8c0a4f17e..fc5fbb579 100644
--- a/interfaces/cython/cantera/test/test_convert.py
+++ b/interfaces/cython/cantera/test/test_convert.py
@@ -348,6 +348,13 @@ class chemkinConverterTest(utilities.CanteraTest):
                         outName=pjoin(self.test_work_dir, 'h2o2_transport_bad_geometry.cti'),
                         quiet=True)
 
+    def test_transport_float_geometry(self):
+        with self.assertRaises(ck2cti.InputParseError):
+            convertMech(pjoin(self.test_data_dir, 'h2o2.inp'),
+                        transportFile=pjoin(self.test_data_dir, 'h2o2-float-geometry-tran.dat'),
+                        outName=pjoin(self.test_work_dir, 'h2o2_transport_float_geometry.cti'),
+                        quiet=True)
+
     def test_empty_reaction_section(self):
         convertMech(pjoin(self.test_data_dir, 'h2o2_emptyReactions.inp'),
                     outName=pjoin(self.test_work_dir, 'h2o2_emptyReactions.cti'),
diff --git a/test/data/h2o2-float-geometry-tran.dat b/test/data/h2o2-float-geometry-tran.dat
new file mode 100644
index 000000000..dbfefc4cc
--- /dev/null
+++ b/test/data/h2o2-float-geometry-tran.dat
@@ -0,0 +1,9 @@
+AR                 0   136.500     3.330     0.000     0.000     0.000
+H                  0.00   145.000     2.050     0.000     0.000     0.000
+H2                 1.00    38.000     2.920     0.000     0.790   280.000
+H2O                2.00   572.400     2.605     1.844     0.000     4.000
+H2O2               2   107.400     3.458     0.000     0.000     3.800
+HO2                2   107.400     3.458     0.000     0.000     1.000 ! *
+O                  0    80.000     2.750     0.000     0.000     0.000
+O2                 1   107.400     3.458     0.000     1.600     3.800
+OH                 1    80.000     2.750     0.000     0.000     0.000