diff --git a/HISTORY.rst b/HISTORY.rst
index 5a3d1c572f..fd84f34080 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -42,12 +42,13 @@ Unreleased Changes
     * Fixed a bug in HRA where the model would error when all exposure and
       consequence criteria were skipped for a single habitat. The model now
       correctly handles this case. https://github.com/natcap/invest/issues/1250
+    * Tables in the .xls format are no longer supported. This format was
+      deprecated by ``pandas``. (`#1271 <https://github.com/natcap/invest/issues/1271>`_)
 * Scenic Quality
     * The Scenic Quality model will now raise an error when it encounters a
       geometry that is not a simple Point.  This is in line with the user's
       guide chapter.  https://github.com/natcap/invest/issues/1245
 
-
 3.13.0 (2023-03-17)
 -------------------
 * General
diff --git a/src/natcap/invest/hra.py b/src/natcap/invest/hra.py
index dee30fddfe..63ea8ccfb5 100644
--- a/src/natcap/invest/hra.py
+++ b/src/natcap/invest/hra.py
@@ -1834,10 +1834,10 @@ def _translate_op(*input_arrays):
 
 def _open_table_as_dataframe(table_path, **kwargs):
     extension = os.path.splitext(table_path)[1].lower()
-    # Technically, pandas.read_excel can handle xls, xlsx, xlsm, xlsb, odf, ods
-    # and odt file extensions, but I have not tested anything other than XLS
-    # and XLSX, so leaving this as-is from the prior HRA implementation.
-    if extension in {'.xls', '.xlsx'}:
+    # Technically, pandas.read_excel can handle xlsx, xlsm, xlsb, odf, ods
+    # and odt file extensions, but I have not tested anything other than
+    # XLSX, so leaving this as-is from the prior HRA implementation.
+    if extension == '.xlsx':
         excel_df = pandas.read_excel(table_path, **kwargs)
         excel_df.columns = excel_df.columns.str.lower()
         excel_df['path'] = excel_df['path'].apply(
@@ -1906,7 +1906,7 @@ def _parse_criteria_table(criteria_table_path, target_composite_csv_path):
     included in this table.
 
     Args:
-        criteria_table_path (string): The path to a CSV, XLS or XLSX file on
+        criteria_table_path (string): The path to a CSV or XLSX file on
             disk.
         target_composite_csv_path (string): The path to where a new CSV should
             be written containing similar information but in a more easily
@@ -1921,7 +1921,7 @@ def _parse_criteria_table(criteria_table_path, target_composite_csv_path):
     # This function requires that the table is read as a numpy array, so it's
     # easiest to read the table directly.
     extension = os.path.splitext(criteria_table_path)[1].lower()
-    if extension in {'.xls', '.xlsx'}:
+    if extension == '.xlsx':
         df = pandas.read_excel(criteria_table_path, header=None)
     else:
         df = pandas.read_csv(criteria_table_path, header=None, sep=None,
@@ -2476,7 +2476,7 @@ def _override_datastack_archive_criteria_table_path(
     """
     args_key = 'criteria_table_path'
     extension = os.path.splitext(criteria_table_path)[1].lower()
-    if extension in {'.xls', '.xlsx'}:
+    if extension == '.xlsx':
         df = pandas.read_excel(criteria_table_path, header=None)
     else:
         df = pandas.read_csv(criteria_table_path, header=None, sep=None,
diff --git a/tests/test_hra.py b/tests/test_hra.py
index d7f096d2e4..07b6b15c6c 100644
--- a/tests/test_hra.py
+++ b/tests/test_hra.py
@@ -758,7 +758,6 @@ def test_table_format_loading(self):
         expected_df['path'] = [os.path.join(self.workspace_dir, 'foo.tif')]
 
         for filename, func in [('target.csv', source_df.to_csv),
-                               ('target.xls', source_df.to_excel),
                                ('target.xlsx', source_df.to_excel)]:
             full_filepath = os.path.join(self.workspace_dir, filename)
             func(full_filepath, index=False)