diff --git a/components/de_amp/browser/de_amp_util.cc b/components/de_amp/browser/de_amp_util.cc
index a7ce66323198..cb3b39f59f12 100644
--- a/components/de_amp/browser/de_amp_util.cc
+++ b/components/de_amp/browser/de_amp_util.cc
@@ -18,8 +18,11 @@ namespace {
// Check for "amp" or "⚡" in tag
// https://amp.dev/documentation/guides-and-tutorials/learn/spec/amphtml/?format=websites#ampd
constexpr char kGetHtmlTagPattern[] = "(<\\s*?html\\s.*?>)";
+// To see the expected behaviour of this regex, please see unit tests in
+// de_amp_util_unittest.cc
constexpr char kDetectAmpPattern[] =
- "(?:<.*?\\s.*?(amp|⚡|amp=\"\\s*\"|amp='\\s*')(?:\\s.*?>|>|/>))";
+ "(?:<.*?\\s.*?(amp|⚡|⚡=\"\\s*\"|⚡=\'\\s*\'|amp=\"\\s*\"|amp='\\s*')(?:\\s.*"
+ "?>|>|/>))";
// Look for canonical link tag and get href
// https://amp.dev/documentation/guides-and-tutorials/learn/spec/amphtml/?format=websites#canon
constexpr char kFindCanonicalLinkTagPattern[] =
diff --git a/components/de_amp/browser/test/de_amp_util_unittest.cc b/components/de_amp/browser/test/de_amp_util_unittest.cc
index 98c9c397063d..e4a0862b675a 100644
--- a/components/de_amp/browser/test/de_amp_util_unittest.cc
+++ b/components/de_amp/browser/test/de_amp_util_unittest.cc
@@ -62,6 +62,39 @@ TEST(DeAmpUtilUnitTest, DetectAmpWithWordAmpNotAtEnd) {
CheckFindCanonicalLinkResult("https://abc.com", body, true);
}
+TEST(DeAmpUtilUnitTest, DetectAmpWithAmpEmptyAttribute) {
+ const std::string body =
+ ""
+ ""
+ ""
+ ""
+ ""
+ "";
+ CheckFindCanonicalLinkResult("https://abc.com", body, true);
+}
+
+TEST(DeAmpUtilUnitTest, DetectAmpWithEmojiEmptyAttribute) {
+ const std::string body =
+ ""
+ ""
+ ""
+ ""
+ ""
+ "";
+ CheckFindCanonicalLinkResult("https://abc.com", body, true);
+}
+
+TEST(DeAmpUtilUnitTest, DetectAmpWithEmojiEmptyAttributeSingleQuotes) {
+ const std::string body =
+ ""
+ ""
+ ""
+ ""
+ ""
+ "";
+ CheckFindCanonicalLinkResult("https://abc.com", body, true);
+}
+
TEST(DeAmpUtilUnitTest, DetectAmpMixedCase) {
const std::string body =
"\n"