diff --git a/num-macros/Cargo.toml b/num-macros/Cargo.toml
index c4f99f9..47d5a27 100644
--- a/num-macros/Cargo.toml
+++ b/num-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "num-macros"
-version = "0.1.26"
+version = "0.1.27"
 authors = ["The Rust Project Developers"]
 license = "MIT/Apache-2.0"
 homepage = "https://github.com/rust-lang/num"
diff --git a/num-macros/src/lib.rs b/num-macros/src/lib.rs
index b75c6bb..e1c1243 100644
--- a/num-macros/src/lib.rs
+++ b/num-macros/src/lib.rs
@@ -64,6 +64,7 @@ pub fn expand_deriving_from_primitive(cx: &mut ExtCtxt,
     let inline = cx.meta_word(span, InternedString::new("inline"));
     let attrs = vec!(cx.attribute(span, inline));
     let trait_def = TraitDef {
+        is_unsafe: false,
         span: span,
         attributes: Vec::new(),
         path: path!(num::FromPrimitive),