diff --git a/src/libsyntax_ext/deriving/generic/mod.rs b/src/libsyntax_ext/deriving/generic/mod.rs
index 5fecd13db98..026277413b0 100644
--- a/src/libsyntax_ext/deriving/generic/mod.rs
+++ b/src/libsyntax_ext/deriving/generic/mod.rs
@@ -410,7 +410,8 @@ pub fn expand_ext(self,
                     _ => {
                         // Non-ADT derive is an error, but it should have been
                         // set earlier; see
-                        // libsyntax/ext/expand.rs:MacroExpander::expand()
+                        // libsyntax_expand/expand.rs:MacroExpander::fully_expand_fragment()
+                        // libsyntax_expand/base.rs:Annotatable::derive_allowed()
                         return;
                     }
                 };
@@ -461,7 +462,8 @@ pub fn expand_ext(self,
             _ => {
                 // Non-Item derive is an error, but it should have been
                 // set earlier; see
-                // libsyntax/ext/expand.rs:MacroExpander::expand()
+                // libsyntax_expand/expand.rs:MacroExpander::fully_expand_fragment()
+                // libsyntax_expand/base.rs:Annotatable::derive_allowed()
                 return;
             }
         }
diff --git a/src/libsyntax_ext/deriving/mod.rs b/src/libsyntax_ext/deriving/mod.rs
index a98cce1fd61..db61eef01fc 100644
--- a/src/libsyntax_ext/deriving/mod.rs
+++ b/src/libsyntax_ext/deriving/mod.rs
@@ -89,7 +89,8 @@ fn inject_impl_of_structural_trait(cx: &mut ExtCtxt<'_>,
         _ => {
             // Non-Item derive is an error, but it should have been
             // set earlier; see
-            // libsyntax/ext/expand.rs:MacroExpander::expand()
+            // libsyntax_expand/expand.rs:MacroExpander::fully_expand_fragment()
+            // libsyntax_expand/base.rs:Annotatable::derive_allowed()
             return;
         }
     };