diff --git a/examples/xml/basic/geometry.xml b/examples/xml/basic/geometry.xml
index b7de2c1346..b30884f8ca 100644
--- a/examples/xml/basic/geometry.xml
+++ b/examples/xml/basic/geometry.xml
@@ -5,11 +5,11 @@
   <cell id="1" universe="0" fill="37" region="-2" />
   <cell id="100" universe="37" material="40" region="-1" />
   <cell id="101" universe="37" material="41" region="1" />
-  <cell id="2" universe="0" material="41" surfaces = "2 -3" />
+  <cell id="2" universe="0" material="41" region="2 -3" />
 
   <!-- Defition of Surfaces -->
   <surface id="1" type="z-cylinder" coeffs="0 0 7" />
   <surface id="2" type="z-cylinder" coeffs="0 0 9" />
   <surface id="3" type="z-cylinder" coeffs="0 0 11" boundary="vacuum" />
-    
+
 </geometry>
diff --git a/examples/xml/reflective/geometry.xml b/examples/xml/reflective/geometry.xml
index 664ef0705f..51cdf1ecb0 100644
--- a/examples/xml/reflective/geometry.xml
+++ b/examples/xml/reflective/geometry.xml
@@ -5,15 +5,15 @@
   <cell id="1">
     <universe>0</universe>
     <material>1</material>
-    <surfaces>1 -2 3 -4 5 -6</surfaces>
+    <region>1 -2 3 -4 5 -6</region>
   </cell>
 
   <!-- Defition of Surfaces -->
   <surface id="1" type="x-plane" coeffs="-1" boundary="vacuum" />
   <surface id="2" type="x-plane" coeffs="1" boundary="vacuum" />
-  <surface id="3" type="y-plane" coeffs="-1" boundary="reflective" /> 
+  <surface id="3" type="y-plane" coeffs="-1" boundary="reflective" />
   <surface id="4" type="y-plane" coeffs="1" boundary="reflective" />
-  <surface id="5" type="z-plane" coeffs="-1" boundary="reflective" /> 
+  <surface id="5" type="z-plane" coeffs="-1" boundary="reflective" />
   <surface id="6" type="z-plane" coeffs="1" boundary="reflective" />
-    
+
 </geometry>
diff --git a/scripts/openmc-update-inputs b/scripts/openmc-update-inputs
index f2e5308d02..1ff70d0505 100755
--- a/scripts/openmc-update-inputs
+++ b/scripts/openmc-update-inputs
@@ -1,14 +1,15 @@
 #!/usr/bin/env python
 """Update OpenMC's input XML files to the latest format.
 
-Usage information can be obtained by running 'update_inputs.py --help':
+Usage information can be obtained by running 'openmc-update-inputs --help':
 
-usage: update_lattices.py [-h] IN [IN ...]
+usage: openmc-update-inputs [-h] IN [IN ...]
 
-Update lattices in geometry.xml files to the latest format. This will remove
-'outside' attributes/elements and replace them with 'outer' attributes. Note
-that this script will not delete the given files; it will append '.original'
-to the given files and write new ones.
+Update geometry.xml files to the latest format. This will remove 'outside'
+attributes/elements from lattices and replace them with 'outer' attributes. For
+'cell' elements, any 'surfaces' attributes/elements will be renamed
+'region'. Note that this script will not delete the given files; it will append
+'.original' to the given files and write new ones.
 
 positional arguments:
   IN          Input geometry.xml file(s).
@@ -173,9 +174,6 @@ def update_geometry(geometry_root):
     root = geometry_root
     was_updated = False
 
-    # Ignore files that do not contain lattices.
-    if all([child.tag != 'lattice' for child in root]): return False
-
     # Get a set of already-used universe and cell ids.
     uids = get_universe_ids(root)
     cids = get_cell_ids(root)
@@ -233,6 +231,17 @@ def update_geometry(geometry_root):
             del lat.attrib['width']
             was_updated = True
 
+    # Change 'surfaces' to 'region' in cell definitions
+    for cell in root.iter('cell'):
+        elem = cell.find('surfaces')
+        if elem is not None:
+            elem.tag = 'region'
+            was_updated = True
+        if 'surfaces' in cell.attrib:
+            cell.attrib['region'] = cell.attrib['surfaces']
+            del cell.attrib['surfaces']
+            was_updated = True
+
     return was_updated
 
 
diff --git a/tests/test_cmfd_feed/geometry.xml b/tests/test_cmfd_feed/geometry.xml
index 57c4aa2285..73ea679c4c 100644
--- a/tests/test_cmfd_feed/geometry.xml
+++ b/tests/test_cmfd_feed/geometry.xml
@@ -4,7 +4,7 @@
 <!-- Definition of Cells -->
   <cell id="1">
     <universe>0</universe>
-    <surfaces>-1 2 -3 4 -5 6</surfaces>
+    <region>-1 2 -3 4 -5 6</region>
     <material>1</material>
   </cell>
 
@@ -39,5 +39,5 @@
     <coeffs>-1</coeffs>
     <boundary>reflective</boundary>
   </surface>
-   
+
 </geometry>
diff --git a/tests/test_cmfd_nofeed/geometry.xml b/tests/test_cmfd_nofeed/geometry.xml
index 57c4aa2285..73ea679c4c 100644
--- a/tests/test_cmfd_nofeed/geometry.xml
+++ b/tests/test_cmfd_nofeed/geometry.xml
@@ -4,7 +4,7 @@
 <!-- Definition of Cells -->
   <cell id="1">
     <universe>0</universe>
-    <surfaces>-1 2 -3 4 -5 6</surfaces>
+    <region>-1 2 -3 4 -5 6</region>
     <material>1</material>
   </cell>
 
@@ -39,5 +39,5 @@
     <coeffs>-1</coeffs>
     <boundary>reflective</boundary>
   </surface>
-   
+
 </geometry>