Fixes while writing lalrpop parser
diff --git a/src/generics.rs b/src/generics.rs
index 2a00787..05d351f 100644
--- a/src/generics.rs
+++ b/src/generics.rs
@@ -110,7 +110,7 @@
         life: lifetime >>
         bounds: opt_vec!(preceded!(
             punct!(":"),
-            separated_nonempty_list!(punct!(","), lifetime)
+            separated_nonempty_list!(punct!("+"), lifetime)
         )) >>
         (LifetimeDef {
             lifetime: life,