diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index fa541b2..828d421 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -5,10 +5,12 @@ on:
     branches:
       - master
       - maintenance/2.2.x
+      - maintenance/2.3.x
   pull_request:
     branches:
       - master
       - maintenance/2.2.x
+      - maintenance/2.3.x
     types: [opened, synchronize, reopened]
 
 jobs:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a88de7c..ab002a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Version 2.4 (in development)
 
+## Version 2.3.1 (2025-08-04)
+
 ### New features
 
 * [Pull Request 325](https://github.com/MassimoCimmino/pygfunction/pull/325) - Borefields and boreholes can now be concatenated using the `+` operator, e.g. using `new_field = field_1 + field_2`.
diff --git a/pygfunction/gfunction.py b/pygfunction/gfunction.py
index f80a9fb..0edad34 100644
--- a/pygfunction/gfunction.py
+++ b/pygfunction/gfunction.py
@@ -372,11 +372,13 @@ def from_static_params(cls,
             Pipe thermal conductivity (in W/m-K).
         fluid_str: str, optional
             The mixer for this application should be one of:
+
                 - 'Water' - Complete water solution
                 - 'MEG' - Ethylene glycol mixed with water
                 - 'MPG' - Propylene glycol mixed with water
                 - 'MEA' - Ethanol mixed with water
                 - 'MMA' - Methanol mixed with water
+
         fluid_concentration_pct: float, optional
             Mass fraction of the mixing fluid added to water (in %).
             Lower bound = 0. Upper bound is dependent on the mixture.
diff --git a/pygfunction/networks.py b/pygfunction/networks.py
index 719f364..8b5eb0b 100644
--- a/pygfunction/networks.py
+++ b/pygfunction/networks.py
@@ -147,13 +147,15 @@ def from_static_params(cls,
             Fluid mass flow rate into the network of boreholes (in kg/s).
         epsilon : float
             Pipe roughness (in meters).
-       fluid_str: str
+        fluid_str: str
             The mixer for this application should be one of:
+
                 - 'Water' - Complete water solution
                 - 'MEG' - Ethylene glycol mixed with water
                 - 'MPG' - Propylene glycol mixed with water
                 - 'MEA' - Ethanol mixed with water
                 - 'MMA' - Methanol mixed with water
+
         fluid_concentration_pct: float
             Mass fraction of the mixing fluid added to water (in %).
             Lower bound = 0. Upper bound is dependent on the mixture.