diff --git a/notmuch/src/lib.rs b/notmuch/src/lib.rs
index 714c89e..39042f4 100644
--- a/notmuch/src/lib.rs
+++ b/notmuch/src/lib.rs
@@ -518,7 +518,7 @@ impl Notmuch {
     }
 
     pub fn count(&self, query: &str) -> Result<usize, NotmuchError> {
-        let res = self.run_notmuch(["count", query])?;
+        let res = self.run_notmuch(["count", "--output=threads", query])?;
         // Strip '\n' from res.
         let s = std::str::from_utf8(&res[..res.len() - 1])?;
         Ok(s.parse()?)