diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 675afb756db75aed151c95b9ffbfcea8f10c91b5..7c1c17a3c7cbae4fb1a075d04058823a7c7d9007 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -29,7 +29,7 @@ stages:
 tests-and-coverage:
   stage: pretest
   extends: .every-commit
-  image: i10git.cs.fau.de:5005/pycodegen/pycodegen/full
+  image: i10git.cs.fau.de:5005/pycodegen/pycodegen/full:cupy12.3
   script:
     # - pip install sympy --upgrade
     - export NUM_CORES=$(nproc --all)
diff --git a/src/lbmpy/boundaries/wall_function_models.py b/src/lbmpy/boundaries/wall_function_models.py
index 4f627787c0ce3417538df75171ed529508ee3625..e1962673894981210ccaf8e785658c548f86fd1f 100644
--- a/src/lbmpy/boundaries/wall_function_models.py
+++ b/src/lbmpy/boundaries/wall_function_models.py
@@ -157,7 +157,7 @@ class MuskerLaw(ImplicitWallFunctionModel):
         def law(u_p, y_p):
             arctan = sp.Float(5.424) * sp.atan(sp.Float(0.119760479041916168) * y_p - sp.Float(0.488023952095808383))
             logarithm = (sp.Float(0.434) * sp.log((y_p + sp.Float(10.6)) ** sp.Float(9.6)
-                                                  / (y_p ** 2 - sp.Float(8.15) * y_p + sp.Float(86)) ** 2, 10))
+                                                  / (y_p ** 2 - sp.Float(8.15) * y_p + sp.Float(86)) ** 2))
             return (arctan + logarithm - sp.Float(3.50727901936264842)) - u_p
 
         u_plus = velocity_symbol / self.u_tau[0]