diff --git a/src/webdav4/client.py b/src/webdav4/client.py
index 8c41527..8651466 100644
--- a/src/webdav4/client.py
+++ b/src/webdav4/client.py
@@ -293,9 +293,11 @@ def options(self, path: str = "") -> Set[str]:
         detected_features = FeatureDetection(resp)
         return detected_features.dav_compliances
 
-    def join_url(self, path: str) -> URL:
+    def join_url(self, path: str, add_trailing_slash: bool = False) -> URL:
         """Join resource path with base url of the webdav server."""
-        return join_url(self.base_url, path)
+        return join_url(
+            self.base_url, path, add_trailing_slash=add_trailing_slash
+        )
 
     def propfind(
         self, path: str, data: str = None, headers: "HeaderTypes" = None
@@ -341,13 +343,17 @@ def set_property(self) -> None:
         """Setting additional property to a resource."""
 
     def _request(
-        self, method: str, path: str, **kwargs: Any
+        self,
+        method: str,
+        path: str,
+        add_trailing_slash: bool = False,
+        **kwargs: Any,
     ) -> "HTTPResponse":
         """Internal method for sending request to the server.
 
         It handles joining path correctly and checks for common http errors.
         """
-        url = self.join_url(path)
+        url = self.join_url(path, add_trailing_slash=add_trailing_slash)
         http_resp = self.http.request(method, url, **kwargs)
 
         if http_resp.status_code == HTTPStatus.NOT_FOUND:
@@ -448,7 +454,9 @@ def copy(
 
     def mkdir(self, path: str) -> None:
         """Create a collection."""
-        call = wrap_fn(self.request, HTTPMethod.MKCOL, path)
+        call = wrap_fn(
+            self.request, HTTPMethod.MKCOL, path, add_trailing_slash=True
+        )
         try:
             http_resp = self.with_retry(call)
         except HTTPError as exc:
diff --git a/src/webdav4/urls.py b/src/webdav4/urls.py
index f2e6994..1188d96 100644
--- a/src/webdav4/urls.py
+++ b/src/webdav4/urls.py
@@ -15,10 +15,15 @@ def normalize_path(path: str) -> str:
     return strip_leading_slash(path)
 
 
-def join_url(base_url: URL, path: str) -> URL:
+def join_url(
+    base_url: URL, path: str, add_trailing_slash: bool = False
+) -> URL:
     """Joins base url with a path."""
     base_path = base_url.path
-    return base_url.copy_with(path=join_url_path(base_path, path))
+    path = join_url_path(base_path, path)
+    if add_trailing_slash:
+        path += "/"
+    return base_url.copy_with(path=path)
 
 
 def join_url_path(hostname: str, path: str) -> str:
diff --git a/tests/test_client.py b/tests/test_client.py
index f01b0ac..0a4fbc4 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -24,6 +24,7 @@
     ResourceNotFound,
 )
 from webdav4.http import Client as HTTPClient
+from webdav4.http import Method
 from webdav4.http import Method as HTTPMethod
 from webdav4.urls import URL
 
@@ -402,6 +403,27 @@ def test_mkdir_forbidden_operations(client: Client, server_address: URL):
     )
 
 
+@pytest.mark.parametrize(
+    "path", ["collections", "/collections", "/collections", "/collections/"]
+)
+def test_mkdir_sends_a_trailing_slash(path: str):
+    """Test that mkdir sends a request to the url with a trailing slash.
+
+    See: https://github.com/skshetry/webdav4/issues/55
+    """
+    from httpx import Request, Response
+
+    response = Response(200, request=Request(Method.MKCOL, "url"))
+    client = Client(
+        "http://example.org", http_client=mock.MagicMock(return_value=response)
+    )
+    with mock.patch.object(client.http, "request", return_value=response) as m:
+        client.mkdir(path)
+        assert m.call_args == mock.call(
+            "MKCOL", URL("http://example.org/collections/")
+        )
+
+
 def test_remove_collection(storage_dir: TmpDir, client: Client):
     """Test trying to remove a collection resource."""
     storage_dir.gen({"data": {"foo": "foo"}})