diff --git a/cppwg/utils/utils.py b/cppwg/utils/utils.py
index bdd38d7..1a6e379 100644
--- a/cppwg/utils/utils.py
+++ b/cppwg/utils/utils.py
@@ -172,7 +172,7 @@ def read_source_file(
     return source
 
 
-def str_to_num(expr: str) -> float:
+def str_to_num(expr: str, integer: bool = False) -> Number:
     """
     Convert a literal string expression to a number e.g. "(-1)" to -1.
 
@@ -183,12 +183,14 @@ def str_to_num(expr: str) -> float:
 
     Returns
     -------
-    float
+    Number
         The converted number, or None if the conversion fails
     """
     try:
         result = ast.literal_eval(expr.strip())
         if isinstance(result, Number):
+            if integer:
+                return int(result)
             return float(result)
     except (SyntaxError, TypeError, ValueError):
         pass
diff --git a/cppwg/writers/constructor_writer.py b/cppwg/writers/constructor_writer.py
index 624cf6f..e1cb032 100644
--- a/cppwg/writers/constructor_writer.py
+++ b/cppwg/writers/constructor_writer.py
@@ -188,9 +188,11 @@ def generate_wrapper(self) -> str:
             ):
                 # Try to convert "(-1)" to "-1" etc.
                 default_value = str(arg.default_value)
-                num = utils.str_to_num(default_value)
-                if num is not None:
-                    default_value = str(num)
+                value = utils.str_to_num(
+                    default_value, integer="int" in str(arg.decl_type)
+                )
+                if value is not None:
+                    default_value = str(value)
 
                 # Check for template params in default value
                 if self.template_params:
diff --git a/cppwg/writers/free_function_writer.py b/cppwg/writers/free_function_writer.py
index 39215f1..1681110 100644
--- a/cppwg/writers/free_function_writer.py
+++ b/cppwg/writers/free_function_writer.py
@@ -49,14 +49,16 @@ def generate_wrapper(self) -> str:
         # e.g. with default values: ', py::arg("foo") = 1, py::arg("bar") = 2'
         default_args = ""
         if not self.free_function_info.hierarchy_attribute("exclude_default_args"):
-            for argument in self.free_function_info.decls[0].arguments:
-                default_args += f', py::arg("{argument.name}")'
-                if argument.default_value is not None:
+            for arg in self.free_function_info.decls[0].arguments:
+                default_args += f', py::arg("{arg.name}")'
+                if arg.default_value is not None:
                     # Try to convert "(-1)" to "-1" etc.
-                    default_value = str(argument.default_value)
-                    num = utils.str_to_num(default_value)
-                    if num is not None:
-                        default_value = str(num)
+                    default_value = str(arg.default_value)
+                    value = utils.str_to_num(
+                        default_value, integer="int" in str(arg.decl_type)
+                    )
+                    if value is not None:
+                        default_value = str(value)
                     default_args += f" = {default_value}"
 
         # Add the free function wrapper code to the wrapper string
diff --git a/cppwg/writers/method_writer.py b/cppwg/writers/method_writer.py
index 4ccc056..07cd99b 100644
--- a/cppwg/writers/method_writer.py
+++ b/cppwg/writers/method_writer.py
@@ -158,9 +158,11 @@ def generate_wrapper(self) -> str:
             ):
                 # Try to convert "(-1)" to "-1" etc.
                 default_value = str(arg.default_value)
-                num = utils.str_to_num(default_value)
-                if num is not None:
-                    default_value = str(num)
+                value = utils.str_to_num(
+                    default_value, integer="int" in str(arg.decl_type)
+                )
+                if value is not None:
+                    default_value = str(value)
 
                 # Check for template params in default value
                 if self.template_params: