diff --git a/src/converter.py b/src/converter.py
index e10fb0c..61a1a72 100644
--- a/src/converter.py
+++ b/src/converter.py
@@ -76,6 +76,8 @@ def convert(data: dict, last_modified: datetime, target_format: str) -> str:
     match target_format:
         case "adguard":
             return adguard_conversion(last_modified, data)
+        case "ublacklist":
+            return ublacklist_conversion(last_modified, data)
         case _:
             raise UnsupportedTargetFormatError
 
@@ -97,6 +99,23 @@ def adguard_conversion(last_modified: datetime, data: dict) -> list[str]:
     return "\n".join(output)
 
 
+def ublacklist_conversion(last_modified: datetime, data: dict) -> list[str]:
+    header_lines: list[str] = [
+        f"# Blocking list automatically generated at {last_modified.strftime('%Y-%m-%d %H:%M:%S %Z%z')}",
+        "# Created with ❤️ by internet-czas-dzialac.pl",
+    ]
+
+    output: list[str] = list(header_lines)
+
+    for entry in data["domains"]:
+        fqdn = entry["fqdn"]
+        if entry.get("exclude", False):
+            continue
+        output.append(f"*://*.{fqdn}/*")
+
+    return "\n".join(output)
+
+
 def dump_output(data: str, output_file: str) -> None:
     try:
         directory = os.path.dirname(output_file)