diff --git a/html/cross-origin-opener-policy/header-parsing.https.html b/html/cross-origin-opener-policy/header-parsing.https.html
index 0fef85f6e25239..94fef0a38c291b 100644
--- a/html/cross-origin-opener-policy/header-parsing.https.html
+++ b/html/cross-origin-opener-policy/header-parsing.https.html
@@ -13,24 +13,32 @@
 
   // None of the following should be recognized as "same-origin" (hence the
   // "expected opener" value of `true`).
-  [SAME_ORIGIN, "same\u2014origin;", true], // non-ASCII character (em dash)
+  [SAME_ORIGIN, "same\u2014origin", true], // non-ASCII character (em dash)
   [SAME_ORIGIN, "same-origin;", true],
-  [SAME_ORIGIN, "same-origin\0", true],
   [SAME_ORIGIN, "\u000bsame-origin\u000b", true], // vertical tab
   [SAME_ORIGIN, "\u000csame-origin\u000c", true], // form feed
   [SAME_ORIGIN, "\u000dsame-origin\u000d", true], // carriage return
   [SAME_ORIGIN, "Same-origin", true],
-  [SAME_ORIGIN, "same-origin; foo=bar", true],
-  [SAME_ORIGIN, "\"same-origin\"", true], // HTTP structured header "string" item
-  [SAME_ORIGIN, "*c2FtZS1vcmlnaW4=*", true], // HTTP structured header "byte sequence" item
+  [SAME_ORIGIN, "same-origin;\tfoo=bar", true],
+  [SAME_ORIGIN, "same-origin ;foo=bar", true],
+  [SAME_ORIGIN, "same-origin; foo=bar;", true],
+  [SAME_ORIGIN, "\"same-origin\"", true], // HTTP structured fields "string" item
+  [SAME_ORIGIN, ":c2FtZS1vcmlnaW4=:", true], // HTTP structured fields "byte sequence" item
+  [SAME_ORIGIN, "?1", true], // HTTP structured fields "boolean" item
+  [SAME_ORIGIN, "1", true], // HTTP structured fields "integer or decimal" item
+  [SAME_ORIGIN, "$same-origin", true], // the item type is unrecognized
   [SAME_ORIGIN, "same-origin same-origin", true],
   [SAME_ORIGIN, "same-origin,same-origin", true],
-  [SAME_ORIGIN, "same-origin;same-origin", true],
+  [SAME_ORIGIN, "\tsame-origin", true],
+  [SAME_ORIGIN, "same-origin\t", true],
+  [SAME_ORIGIN, "*same-origin ", true],
 
   // All of the following should be recognized as "same-origin" (hence the
   // "expected opener" value of `false`).
-  [SAME_ORIGIN, " \tsame-origin", false],
-  [SAME_ORIGIN, "same-origin\t ", false],
+  [SAME_ORIGIN, " same-origin", false],
+  [SAME_ORIGIN, "same-origin ", false],
+  [SAME_ORIGIN, "same-origin;same-origin", false],
+  [SAME_ORIGIN, "same-origin; foo=bar", false],
 ];
 
 run_coop_tests("unspecified", tests);
diff --git a/html/cross-origin-opener-policy/resources/common.js b/html/cross-origin-opener-policy/resources/common.js
index 8a3cd133734dc3..575ebc233432f7 100644
--- a/html/cross-origin-opener-policy/resources/common.js
+++ b/html/cross-origin-opener-policy/resources/common.js
@@ -63,7 +63,7 @@ function run_coop_tests(documentCOOPValueTitle, testArray) {
       coop_test(t, test[0], test[1],
                 `${documentCOOPValueTitle}_to_${test[0].name}_${test[1].replace(/ /g,"-")}`,
                 test[2], () => { t.done(); });
-    }, `${documentCOOPValueTitle} document opening popup to ${test[0].origin} with COOP: "${test[1]}"`);
+    }, `${documentCOOPValueTitle} document opening popup to ${test[0].origin} with COOP: ${format_value(test[1])}`);
   }
 }
 
@@ -91,5 +91,5 @@ function run_coop_test_iframe (documentTitle, iframe_origin, popup_origin, popup
               assert_equals(payload.name, expects_name? name:"", 'name');
       });
       document.body.append(frame);
-  }, `${documentTitle} with ${iframe_origin.name} iframe opening popup a ${popup_origin.name} with COOP: ${popup_coop}`);
-}
\ No newline at end of file
+  }, `${documentTitle} with ${iframe_origin.name} iframe opening popup a ${popup_origin.name} with COOP: ${format_value(popup_coop)}`);
+}