diff --git a/processing/content.py b/processing/content.py
index 0060b89..1d00895 100644
--- a/processing/content.py
+++ b/processing/content.py
@@ -3,7 +3,7 @@ from typing import Any
 
 def summary_to_md(data: dict[str, Any], lang: str = "en", headline: str = ""):
     if "summary" not in data:
-        return
+        return ""
     md = f"{headline}\n\n {data['summary'][lang]}\n\n"
 
     return md
@@ -26,7 +26,7 @@ def experience_to_md(
     subdued_publications: bool = True,
 ):
     if "experience" not in data:
-        return
+        return ""
 
     md = f"{headline}\n\n"
     md += "\\definecolor{publication}{rgb}{0.5,0.5,0.5}\n\n"
@@ -56,7 +56,7 @@ def education_to_md(
     data: dict[str, Any], lang: str = "en", headline: str = "", thesis: bool = True
 ):
     if "education" not in data:
-        return
+        return ""
 
     md = f"{headline}\n\n"
 
@@ -73,7 +73,7 @@ def education_to_md(
 
 def qualifications_to_md(data: dict[str, Any], lang: str = "en", headline: str = ""):
     if "skills" not in data:
-        return
+        return ""
 
     md = f"{headline}\n\n"
     for skillset in data["skills"]: