diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54454dfd6d..22d4dacc92 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@
 
 ## Bug fixes
 
+-   Fix doctests failing due to mismatch in unsorted output.([#990](https://github.com/pybamm-team/PyBaMM/pull/990))
 -   Added extra checks when creating a model, for clearer errors ([#971](https://github.com/pybamm-team/PyBaMM/pull/971))
 -   Fixed `Interpolant` ids to allow processing ([#962](https://github.com/pybamm-team/PyBaMM/pull/962))
 -   Fixed a bug in the initial conditions of the potential pair model ([#954](https://github.com/pybamm-team/PyBaMM/pull/954))
diff --git a/pybamm/parameters_cli.py b/pybamm/parameters_cli.py
index a9a69194fc..e5e45a17a7 100644
--- a/pybamm/parameters_cli.py
+++ b/pybamm/parameters_cli.py
@@ -148,11 +148,11 @@ def list_parameters(arguments=None):
     >>> from pybamm.parameters_cli import list_parameters
     >>> list_parameters(["lithium-ion", "anodes"])
     Available package parameters:
-      * graphite_Ecker2015
       * graphite_Chen2020
-      * graphite_mcmb2528_Marquis2019
-      * graphite_UMBL_Mohtat2020
+      * graphite_Ecker2015
       * graphite_Kim2011
+      * graphite_UMBL_Mohtat2020
+      * graphite_mcmb2528_Marquis2019
     Available local parameters:
     """
     parser = argparse.ArgumentParser(
@@ -179,7 +179,7 @@ def list_parameters(arguments=None):
     root, package_dirs, files = next(os.walk(package_dir))
 
     print("Available package parameters:")
-    for dirname in package_dirs:
+    for dirname in sorted(package_dirs):
         print("  * {}".format(dirname))
 
     local_dir = os.path.join("input", "parameters", args.battery_type, args.component)
@@ -188,5 +188,5 @@ def list_parameters(arguments=None):
     else:
         local_dirs = []
     print("Available local parameters:")
-    for dirname in local_dirs:
+    for dirname in sorted(local_dirs):
         print("  * {}".format(dirname))