diff --git a/biosteam/__init__.py b/biosteam/__init__.py
index 08eabf4e..b955e550 100644
--- a/biosteam/__init__.py
+++ b/biosteam/__init__.py
@@ -13,7 +13,7 @@
 
 """
 from __future__ import annotations
-__version__ = '2.49.3'
+__version__ = '2.49.4'
 
 #: Chemical engineering plant cost index (defaults to 567.5 at 2017).
 CE: float = 567.5 
diff --git a/biosteam/units/adsorption.py b/biosteam/units/adsorption.py
index 0f13a9d3..6c5e1414 100644
--- a/biosteam/units/adsorption.py
+++ b/biosteam/units/adsorption.py
@@ -801,14 +801,14 @@ def plot_fit_isotherm(dct, method):
             if method == 'Langmuir':
                 plt.plot(
                     *dct['linearized prediction'],
-                    label=f'R$^2$ = {round(dct['R2'], 2)}, K={round(dct['K'], 2)}, q$_{{max}}$={round(dct['qmax'], 2)}'
+                    label=f"R$^2$ = {round(dct['R2'], 2)}, K={round(dct['K'], 2)}, q$_{{max}}$={round(dct['qmax'], 2)}"
                 )
                 plt.xlabel('C [mg / L]')
                 plt.ylabel('C / q [g / L]')
             else:
                 plt.plot(
                     *dct['linearized prediction'],
-                    label=f'R$^2$ = {round(dct['R2'], 2)}, K={round(dct['K'], 2)}, n={round(dct['n'], 2)}'
+                    label=f"R$^2$ = {round(dct['R2'], 2)}, K={round(dct['K'], 2)}, n={round(dct['n'], 2)}"
                 )
                 plt.xlabel('log(C)')
                 plt.ylabel('log(q)')
@@ -836,10 +836,10 @@ def plot_fit_isotherm(dct, method):
         R2 = dct['R2']
         plt.plot(
             *dct['linearized prediction'],
-            label=f'R$^2$ = {np.round(R2, 2)}, k={dct['k']:.2g}'
+            label=f"R$^2$ = {np.round(R2, 2)}, k={dct['k']:.2g}"
         )
-        plt.ylabel(f'log((qe - q) / q)')
-        plt.xlabel(f't')
+        plt.ylabel('log((qe - q) / q)')
+        plt.xlabel('t')
         plt.legend()
 
 AdsorptionColumn = SingleComponentAdsorptionColumn
\ No newline at end of file
diff --git a/setup.py b/setup.py
index d7d8b1b9..3d0a68d6 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@
     name='biosteam',
     packages=['biosteam'],
     license='MIT',
-    version='2.49.3',
+    version='2.49.4',
     description='The Biorefinery Simulation and Techno-Economic Analysis Modules',
     long_description=open('README.rst', encoding='utf-8').read(),
     author='Yoel Cortes-Pena',