diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index b9e816baac0dc..6768e0ade4304 100644
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -685,7 +685,7 @@ impl TokenTree {
                 })
             }
 
-            DotEq => unreachable!(),
+            DotEq => joint!('.', Eq),
             OpenDelim(..) | CloseDelim(..) => unreachable!(),
             Whitespace | Comment | Shebang(..) | Eof => unreachable!(),
         };