5 files changed, 32 insertions, 1 deletions
diff --git a/compiler/rustc_passes/locales/en-US.ftl b/compiler/rustc_passes/locales/en-US.ftl
index 0c7e02912d4..8fe8472b216 100644
--- a/compiler/rustc_passes/locales/en-US.ftl
+++ b/compiler/rustc_passes/locales/en-US.ftl
@@ -407,10 +407,10 @@ passes_duplicate_diagnostic_item =
 
 passes_duplicate_diagnostic_item_in_crate =
     duplicate diagnostic item in crate `{$crate_name}`: `{$name}`.
+    .note = the diagnostic item is first defined in crate `{$orig_crate_name}`.
 
 passes_diagnostic_item_first_defined =
     the diagnostic item is first defined here
-    .note = the diagnostic item is first defined in crate `{$orig_crate_name}`.
 
 passes_abi =
     abi: {$abi}
diff --git a/tests/ui/tool-attributes/auxiliary/p1.rs b/tests/ui/tool-attributes/auxiliary/p1.rs
new file mode 100644
index 00000000000..47195c7e9d6
--- /dev/null
+++ b/tests/ui/tool-attributes/auxiliary/p1.rs
@@ -0,0 +1,3 @@
+#![feature(rustc_attrs)]
+#[rustc_diagnostic_item = "Foo"]
+pub struct Foo {}
diff --git a/tests/ui/tool-attributes/auxiliary/p2.rs b/tests/ui/tool-attributes/auxiliary/p2.rs
new file mode 100644
index 00000000000..47195c7e9d6
--- /dev/null
+++ b/tests/ui/tool-attributes/auxiliary/p2.rs
@@ -0,0 +1,3 @@
+#![feature(rustc_attrs)]
+#[rustc_diagnostic_item = "Foo"]
+pub struct Foo {}
diff --git a/tests/ui/tool-attributes/duplicate-diagnostic.rs b/tests/ui/tool-attributes/duplicate-diagnostic.rs
new file mode 100644
index 00000000000..39c2ca1cb86
--- /dev/null
+++ b/tests/ui/tool-attributes/duplicate-diagnostic.rs
@@ -0,0 +1,13 @@
+// aux-build: p1.rs
+// aux-build: p2.rs
+
+// error-pattern: duplicate diagnostic item in crate `p2`
+// error-pattern: note: the diagnostic item is first defined in crate `p1`
+
+#![feature(rustc_attrs)]
+extern crate p1;
+extern crate p2;
+
+#[rustc_diagnostic_item = "Foo"]
+pub struct Foo {} //~ ERROR duplicate diagnostic item found
+fn main() {}
diff --git a/tests/ui/tool-attributes/duplicate-diagnostic.stderr b/tests/ui/tool-attributes/duplicate-diagnostic.stderr
new file mode 100644
index 00000000000..e315fdc7d84
--- /dev/null
+++ b/tests/ui/tool-attributes/duplicate-diagnostic.stderr
@@ -0,0 +1,12 @@
+error: duplicate diagnostic item in crate `p2`: `Foo`.
+   |
+   = note: the diagnostic item is first defined in crate `p1`.
+
+error: duplicate diagnostic item found: `Foo`.
+  --> $DIR/duplicate-diagnostic.rs:12:1
+   |
+LL | pub struct Foo {}
+   | ^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+