diff --git a/novelforge/__init__.py b/novelforge/__init__.py
index 9110c21..3f4f29d 100644
--- a/novelforge/__init__.py
+++ b/novelforge/__init__.py
@@ -233,7 +233,7 @@ def get_llm_log() -> Response:
         log_path = Path(config.LOGS_DIR) / "llm.log"
 
         if not log_path.exists():
-            logger.warning(f"LLM log file not found at {log_path}")
+            logger.warning("LLM log file not found at %s", log_path)
             return jsonify({"entries": []})
 
         try:
diff --git a/novelforge/routes/sessions.py b/novelforge/routes/sessions.py
index b15e9f7..88e13a6 100644
--- a/novelforge/routes/sessions.py
+++ b/novelforge/routes/sessions.py
@@ -68,9 +68,9 @@ def delete_session() -> Response:
         session_file = get_session_file_path()
         if session_file.exists():
             session_file.unlink()
-            logger.info(f"Deleted session file {session_file}")
+            logger.info("Deleted session file %s", session_file)
     except Exception as e:
-        logger.error(f"Failed to delete session file: {e}")
+        logger.error("Failed to delete session file: %s", e)
 
     token = session.get("progress_token", "")
     if token: