diff --git a/xtask/src/npm/nightly.rs b/xtask/src/npm/nightly.rs
index 3ea5fed6d95a..339e4b5d3a07 100644
--- a/xtask/src/npm/nightly.rs
+++ b/xtask/src/npm/nightly.rs
@@ -83,7 +83,7 @@ fn find_first_nightly(prev_version: &semver::Version, date: &str) -> Result<Vers
     }
 
     for i in 1.. {
-        ver.pre = Prerelease::new(&format!("nightly.{}.{}", date, i))?;
+        ver.pre = Prerelease::new(&format!("nightly-{}.{}", date, i))?;
 
         let tag = format!("v{}", ver);