diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 2cbf2b2..cfde63d 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,12 @@
 Changelog
 =========
 
+0.3.1
+-----
+
+- Fix issue when ``source_suffix`` equals ``source_link_suffix``
+  `#29 <https://github.com/jdillard/sphinx-llms-txt/pull/29>`_
+
 0.3.0
 -----
 
diff --git a/sphinx_llms_txt/__init__.py b/sphinx_llms_txt/__init__.py
index aab1c0a..43fe2be 100644
--- a/sphinx_llms_txt/__init__.py
+++ b/sphinx_llms_txt/__init__.py
@@ -12,7 +12,7 @@ from .manager import LLMSFullManager
 from .processor import DocumentProcessor
 from .writer import FileWriter
 
-__version__ = "0.3.0"
+__version__ = "0.3.1"
 
 # Export classes needed by tests
 __all__ = [
diff --git a/sphinx_llms_txt/collector.py b/sphinx_llms_txt/collector.py
index 144938f..d99b237 100644
--- a/sphinx_llms_txt/collector.py
+++ b/sphinx_llms_txt/collector.py
@@ -90,7 +90,13 @@ class DocumentCollector:
 
         # Try to find the source file with any of the valid source suffixes
         for src_suffix in source_suffixes:
-            candidate_file = sources_dir / f"{docname}{src_suffix}{source_link_suffix}"
+            # Avoid duplicate extensions when source_suffix == source_link_suffix
+            if src_suffix == source_link_suffix:
+                candidate_file = sources_dir / f"{docname}{src_suffix}"
+            else:
+                candidate_file = (
+                    sources_dir / f"{docname}{src_suffix}{source_link_suffix}"
+                )
             if candidate_file.exists():
                 return src_suffix
 
diff --git a/sphinx_llms_txt/manager.py b/sphinx_llms_txt/manager.py
index 47fb766..95be747 100644
--- a/sphinx_llms_txt/manager.py
+++ b/sphinx_llms_txt/manager.py
@@ -138,13 +138,22 @@ class LLMSFullManager:
 
             # Build the source file path directly using the known suffix
             if src_suffix:
-                source_file = sources_dir / f"{docname}{src_suffix}{source_link_suffix}"
+                # Avoid duplicate extensions when source_suffix == source_link_suffix
+                if src_suffix == source_link_suffix:
+                    source_file = sources_dir / f"{docname}{src_suffix}"
+                    expected_suffix = src_suffix
+                else:
+                    source_file = (
+                        sources_dir / f"{docname}{src_suffix}{source_link_suffix}"
+                    )
+                    expected_suffix = f"{src_suffix}{source_link_suffix}"
+
                 if source_file.exists():
                     docname_to_file[docname] = source_file
                 else:
                     logger.warning(
                         f"sphinx-llms-txt: Source file not found for: {docname}."
-                        f"Expected: {docname}{src_suffix}{source_link_suffix}"
+                        f"Expected: {docname}{expected_suffix}"
                     )
             else:
                 logger.warning(
@@ -205,7 +214,11 @@ class LLMSFullManager:
             source_suffixes = self._get_source_suffixes()
             all_source_files = []
             for src_suffix in source_suffixes:
-                glob_pattern = f"**/*{src_suffix}{source_link_suffix}"
+                # Avoid duplicate extensions when source_suffix == source_link_suffix
+                if src_suffix == source_link_suffix:
+                    glob_pattern = f"**/*{src_suffix}"
+                else:
+                    glob_pattern = f"**/*{src_suffix}{source_link_suffix}"
                 all_source_files.extend(sources_dir.glob(glob_pattern))
 
             processed_paths = set(file.resolve() for file in docname_to_file.values())
@@ -231,7 +244,12 @@ class LLMSFullManager:
 
                 # Try each source suffix to find which one this file uses
                 for src_suffix in source_suffixes:
-                    combined_suffix = f"{src_suffix}{source_link_suffix}"
+                    # Avoid duplicate extensions when suffixes match
+                    if src_suffix == source_link_suffix:
+                        combined_suffix = src_suffix
+                    else:
+                        combined_suffix = f"{src_suffix}{source_link_suffix}"
+
                     if rel_path.endswith(combined_suffix):
                         docname = rel_path[: -len(combined_suffix)]  # Remove suffix
                         break