diff --git a/test/built-ins/RegExp/unicode_full_case_folding.js b/test/built-ins/RegExp/unicode_full_case_folding.js
new file mode 100644
index 0000000000..ac4ecd5fb0
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+++ b/test/built-ins/RegExp/unicode_full_case_folding.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-runtime-semantics-canonicalize-ch
+description: >
+  Case-insensitive Unicode RegExps should not apply full case folding mappings
+info: |
+  Canonicalize ( _rer_, _ch_ )
+  1. If _rer_.[[Unicode]] is *true* and _rer_.[[IgnoreCase]] is *true*, then
+    a. If the file `CaseFolding.txt` of the Unicode Character Database provides
+      a simple or common case folding mapping for _ch_, return the result of
+      applying that mapping to _ch_.
+    b. Return _ch_.
+
+  See https://unicode.org/Public/UCD/latest/ucd/CaseFolding.txt for the case
+  folding mappings.
+---*/
+
+assert(!/[\u0390]/ui.test("\u1fd3"), "\\u0390 does not match \\u1fd3");
+assert(!/[\u1fd3]/ui.test("\u0390"), "\\u1fd3 does not match \\u0390");
+assert(!/[\u03b0]/ui.test("\u1fe3"), "\\u03b0 does not match \\u1fe3");
+assert(!/[\u1fe3]/ui.test("\u03b0"), "\\u1fe3 does not match \\u03b0");
+assert(!/[\ufb05]/ui.test("\ufb06"), "\\ufb05 does not match \\ufb06");
+assert(!/[\ufb06]/ui.test("\ufb05"), "\\ufb06 does not match \\ufb05");