diff --git a/src/easyreflectometry/project.py b/src/easyreflectometry/project.py
index 5d435293..4d3dc0b2 100644
--- a/src/easyreflectometry/project.py
+++ b/src/easyreflectometry/project.py
@@ -80,11 +80,19 @@ def parameters(self) -> List[Parameter]:
 
     @property
     def count_free_parameters(self) -> int:
-        return sum(1 for parameter in self.parameters if parameter.free)
+        count = 0
+        for parameter in self.parameters:
+            if parameter.free:
+                count += 1
+        return count
 
     @property
     def count_fixed_parameters(self) -> int:
-        return sum(1 for parameter in self.parameters if not parameter.free)
+        count = 0
+        for parameter in self.parameters:
+            if not parameter.free:
+                count += 1
+        return count
 
     @property
     def count_parameter_user_constraints(self) -> int: