diff --git a/tests/rustdoc-js-std/core-std-duplicates.js b/tests/rustdoc-js-std/core-std-duplicates.js
new file mode 100644
index 0000000000000..4647ec6408746
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+++ b/tests/rustdoc-js-std/core-std-duplicates.js
@@ -0,0 +1,21 @@
+// This test ensures that search results are not duplicated between `std` and `core`.
+// Regression test for <https://github.com/rust-lang/rust/issues/131670>.
+
+// exact-check
+
+const EXPECTED = [
+    {
+        'query': 'primitive:char',
+        'others': [
+            { 'path': 'std', 'name': 'char' },
+        ],
+    },
+    {
+        'query': 'char->u32',
+        'others': [
+            { 'path': 'std::u32', 'name': 'from' },
+            { 'path': 'std::char', 'name': 'to_u32' },
+            { 'path': 'std::char', 'name': 'to_digit' },
+        ],
+    },
+];