diff --git a/desktop/crates/cloudreve-api/src/models/uri.rs b/desktop/crates/cloudreve-api/src/models/uri.rs
index db2bca66..fdbec085 100644
--- a/desktop/crates/cloudreve-api/src/models/uri.rs
+++ b/desktop/crates/cloudreve-api/src/models/uri.rs
@@ -499,3 +499,29 @@ pub fn new_my_uri(uid: Option<&str>) -> Result<CrUri> {
         None => CrUri::new("cloudreve://my"),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn join_encodes_spaces_and_special_chars() {
+        let mut uri = CrUri::new("cloudreve://my").unwrap();
+        uri.join(&["dir with spaces", "file name.txt"]);
+
+        let s = uri.to_string();
+        assert!(
+            s.contains("dir%20with%20spaces/file%20name.txt"),
+            "uri: {s}"
+        );
+        assert!(!s.contains(' '));
+        assert_eq!(uri.elements(), vec!["dir with spaces", "file name.txt"]);
+    }
+
+    #[test]
+    fn encoded_uri_roundtrips_spaces() {
+        let uri = CrUri::new("cloudreve://my/a%20b/c%20d.txt").unwrap();
+        assert_eq!(uri.path(), "/a b/c d.txt");
+        assert!(uri.to_string().contains("a%20b/c%20d.txt"));
+    }
+}
diff --git a/desktop/crates/cloudreve-sync/src/drive/utils.rs b/desktop/crates/cloudreve-sync/src/drive/utils.rs
index b0cf6fa7..787a680b 100644
--- a/desktop/crates/cloudreve-sync/src/drive/utils.rs
+++ b/desktop/crates/cloudreve-sync/src/drive/utils.rs
@@ -124,3 +124,29 @@ pub fn notify_shell_change(path: &PathBuf, event: SHCNE_ID) -> Result<()> {
 pub fn notify_shell_change(_path: &PathBuf, _event: u32) -> Result<()> {
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn local_path_to_cr_uri_encodes_spaces() {
+        let uri = local_path_to_cr_uri(
+            PathBuf::from("/sync/dir with spaces/file name.txt"),
+            PathBuf::from("/sync"),
+            "cloudreve://my".to_string(),
+        )
+        .unwrap();
+
+        // The wire URI must carry percent-encoded segments, never raw spaces.
+        assert!(
+            uri.to_string()
+                .contains("dir%20with%20spaces/file%20name.txt"),
+            "uri: {}",
+            uri.to_string()
+        );
+        assert!(!uri.to_string().contains(' '));
+        // The decoded path round-trips to the original names.
+        assert_eq!(uri.path(), "/dir with spaces/file name.txt");
+    }
+}