diff --git a/docs/reference/triplet_store.md b/docs/reference/triplet_store.md
index ad7a0645..ee5c24e6 100644
--- a/docs/reference/triplet_store.md
+++ b/docs/reference/triplet_store.md
@@ -182,7 +182,7 @@ for row in result.bindings:
     store = TripletStore(
         backend="rdf4j",
         endpoint="http://localhost:8080/rdf4j-server",
-        repository_id="semantica",   # passed through **config
+        repository_id="semantica",   # selects the remote repository
     )
     ```
 
diff --git a/semantica/triplet_store/rdf4j_store.py b/semantica/triplet_store/rdf4j_store.py
index c03b64a8..d788ab7b 100644
--- a/semantica/triplet_store/rdf4j_store.py
+++ b/semantica/triplet_store/rdf4j_store.py
@@ -28,7 +28,7 @@ License: MIT
 
 import re
 from typing import Any, Dict, List, Optional
-from urllib.parse import urlparse
+from urllib.parse import quote, urlparse
 
 import requests
 from rdflib import Graph, Literal
@@ -68,6 +68,7 @@ class RDF4JStore:
 
         self.endpoint = endpoint.rstrip("/")
         self.repository_id = repository_id or config.get("repository_id", "default")
+        self._encoded_repository_id = quote(self.repository_id, safe="")
         self.username = config.get("username")
         self.password = config.get("password")
         self.timeout = config.get("timeout", 30)
@@ -79,7 +80,7 @@ class RDF4JStore:
         """Connect to RDF4J server."""
         try:
             # Test connection
-            test_url = f"{self.endpoint}/repositories/{self.repository_id}"
+            test_url = f"{self.endpoint}/repositories/{self._encoded_repository_id}"
             response = requests.get(
                 test_url,
                 timeout=self.timeout,
@@ -100,11 +101,11 @@ class RDF4JStore:
 
     def _get_sparql_endpoint(self) -> str:
         """Get SPARQL query endpoint."""
-        return f"{self.endpoint}/repositories/{self.repository_id}"
+        return f"{self.endpoint}/repositories/{self._encoded_repository_id}"
 
     def _get_update_endpoint(self) -> str:
         """Get SPARQL Update endpoint."""
-        return f"{self.endpoint}/repositories/{self.repository_id}/statements"
+        return f"{self.endpoint}/repositories/{self._encoded_repository_id}/statements"
 
     def _is_construct_query(self, query: str) -> bool:
         """
@@ -163,7 +164,7 @@ class RDF4JStore:
         """
         # RDF4J transaction support
         transaction_url = (
-            f"{self.endpoint}/repositories/{self.repository_id}/transactions"
+            f"{self.endpoint}/repositories/{self._encoded_repository_id}/transactions"
         )
 
         try:
diff --git a/tests/triplet_store/test_rdf4j_store.py b/tests/triplet_store/test_rdf4j_store.py
index 3f630b93..03a9b90b 100644
--- a/tests/triplet_store/test_rdf4j_store.py
+++ b/tests/triplet_store/test_rdf4j_store.py
@@ -23,6 +23,7 @@ CONSTRUCT_QUERY = "CONSTRUCT { ?s ?p ?o } WHERE { ?s ?p ?o }"
 
 
 class TestRDF4JStoreInitialization(unittest.TestCase):
+
     def test_explicit_repository_id_selects_repository(self):
         response = MagicMock(status_code=200)
 
@@ -42,6 +43,49 @@ class TestRDF4JStoreInitialization(unittest.TestCase):
             auth=None,
         )
 
+    def test_repository_id_is_encoded_as_a_single_url_path_segment(self):
+        response = MagicMock(status_code=200)
+
+        with patch(
+            "semantica.triplet_store.rdf4j_store.requests.get",
+            return_value=response,
+        ) as mock_get:
+            store = RDF4JStore(
+                endpoint="http://localhost:8080/rdf4j-server",
+                repository_id="team/repo ?#",
+            )
+
+        self.assertEqual(store.repository_id, "team/repo ?#")
+        mock_get.assert_called_once_with(
+            "http://localhost:8080/rdf4j-server/repositories/team%2Frepo%20%3F%23",
+            timeout=30,
+            auth=None,
+        )
+        self.assertEqual(
+            store._get_sparql_endpoint(),
+            "http://localhost:8080/rdf4j-server/repositories/team%2Frepo%20%3F%23",
+        )
+        self.assertEqual(
+            store._get_update_endpoint(),
+            "http://localhost:8080/rdf4j-server/repositories/"
+            "team%2Frepo%20%3F%23/statements",
+        )
+
+        transaction_response = MagicMock()
+        transaction_response.headers = {"Location": "/transactions/tx-1"}
+        with patch(
+            "semantica.triplet_store.rdf4j_store.requests.post",
+            return_value=transaction_response,
+        ) as mock_post:
+            self.assertEqual(store.begin_transaction(), "tx-1")
+
+        mock_post.assert_called_once_with(
+            "http://localhost:8080/rdf4j-server/repositories/"
+            "team%2Frepo%20%3F%23/transactions",
+            timeout=30,
+            auth=None,
+        )
+
 
 class TestRDF4JStoreIsConstructQuery(unittest.TestCase):
     def test_detects_uppercase(self):