diff --git a/src/vuegen/streamlit_reportview.py b/src/vuegen/streamlit_reportview.py
index 74d5d24..40ce2ce 100644
--- a/src/vuegen/streamlit_reportview.py
+++ b/src/vuegen/streamlit_reportview.py
@@ -1,4 +1,5 @@
 import os
+import re
 import subprocess
 import sys
 from pathlib import Path
@@ -9,6 +10,7 @@
 
 from . import report as r
 from .utils import create_folder, generate_footer, is_url
+from .utils.variables import make_valid_identifier
 
 
 class StreamlitReportView(r.WebAppReportView):
@@ -114,7 +116,15 @@ def generate_report(
                     )
 
                 for subsection in section.subsections:
-                    subsection_name_var = subsection.title.replace(" ", "_")
+                    # ! could add a non-integer to ensure it's a valid identifier
+                    subsection_name_var = make_valid_identifier(subsection.title)
+                    if not subsection_name_var.isidentifier():
+                        self.report.logger.warning(
+                            f"Subsection name '{subsection_name_var}' is not a valid identifier."
+                        )
+                        raise ValueError(
+                            f"Subsection name is not a valid Python identifier: {subsection_name_var}"
+                        )
                     subsection_file_path = (
                         Path(section_name_var) / f"{subsection_name_var}.py"
                     ).as_posix()  # Make sure it's Posix Paths
@@ -336,10 +346,11 @@ def _generate_sections(self, output_dir: str, static_dir: str) -> None:
                         )
                         try:
                             # Create subsection file
+                            _subsection_name = make_valid_identifier(subsection.title)
                             subsection_file_path = (
                                 Path(output_dir)
                                 / section_name_var
-                                / f"{subsection.title.replace(' ', '_')}.py"
+                                / f"{_subsection_name}.py"
                             )
 
                             # Generate content and imports for the subsection
diff --git a/src/vuegen/utils.py b/src/vuegen/utils/__init__.py
similarity index 100%
rename from src/vuegen/utils.py
rename to src/vuegen/utils/__init__.py
diff --git a/src/vuegen/utils/variables.py b/src/vuegen/utils/variables.py
new file mode 100644
index 0000000..7a532b6
--- /dev/null
+++ b/src/vuegen/utils/variables.py
@@ -0,0 +1,12 @@
+import re
+
+
+def make_valid_identifier(name: str) -> str:
+    """Create a valid Python identifier from a given name.
+
+    Used in streamlit report sections to build structure (pages).
+    """
+    ret = re.sub(r"[^a-zA-Z0-9]", "_", name)
+    if not ret[0].isalpha():
+        ret = "_" + ret
+    return ret
diff --git a/tests/utils/test_variables.py b/tests/utils/test_variables.py
new file mode 100644
index 0000000..cc4bae2
--- /dev/null
+++ b/tests/utils/test_variables.py
@@ -0,0 +1,16 @@
+import pytest
+
+from vuegen.utils.variables import make_valid_identifier
+
+test_cases = [
+    ("a.non valid name", "a_non_valid_name"),
+    ("1.non valid name", "_1_non_valid_name"),
+    ("a_valid_name", "a_valid_name"),
+    ("test", "test"),
+]
+
+
+@pytest.mark.parametrize("var_name,expected", test_cases)
+def test_make_valid_identifier(var_name, expected):
+    """Test the make_valid_identifier function."""
+    assert make_valid_identifier(var_name) == expected