diff --git a/Formula/gz-math7.rb b/Formula/gz-math7.rb
index c4de7f9e8..1c4d150ca 100644
--- a/Formula/gz-math7.rb
+++ b/Formula/gz-math7.rb
@@ -44,7 +44,7 @@ def pythons
         .select { |f| f.name.match?(/^python@3\.\d+$/) }
   end
 
-  def python_cmake_arg(python = "python@3.13".to_formula)
+  def python_cmake_arg(python = Formula["python@3.13"])
     "-DPython3_EXECUTABLE=#{python.opt_libexec}/bin/python"
   end
 
diff --git a/Formula/gz-math8.rb b/Formula/gz-math8.rb
index 327e1339a..ece7b078f 100644
--- a/Formula/gz-math8.rb
+++ b/Formula/gz-math8.rb
@@ -37,7 +37,7 @@ def pythons
         .select { |f| f.name.match?(/^python@3\.\d+$/) }
   end
 
-  def python_cmake_arg(python = "python@3.13".to_formula)
+  def python_cmake_arg(python = Formula["python@3.13"])
     "-DPython3_EXECUTABLE=#{python.opt_libexec}/bin/python"
   end