diff --git a/devtools/server/tests/mochitest/inspector-styles-data.html b/devtools/server/tests/mochitest/inspector-styles-data.html
index 029050167399..334b268bfd7c 100644
--- a/devtools/server/tests/mochitest/inspector-styles-data.html
+++ b/devtools/server/tests/mochitest/inspector-styles-data.html
@@ -10,6 +10,8 @@
   .inheritable-rule {
     font-size: 15px;
   }
+  /* Has to be on one line, is such for test */
+  .column-rule { font-size: 20px; } .column-rule { font-size: 25px; }
   .uninheritable-rule {
     background-color: #f06;
   }
@@ -62,7 +64,7 @@
   </div>
 
   <!-- Matched checks -->
-  <div id="matched-parent" class="external-rule inheritable-rule uninheritable-rule" style="color: red;">
+  <div id="matched-parent" class="external-rule inheritable-rule column-rule uninheritable-rule" style="color: red;">
     <div id="matched-test-node" style="font-size: 10px" class="external-rule">
       Here is the test node.
     </div>
diff --git a/devtools/server/tests/mochitest/test_styles-matched.html b/devtools/server/tests/mochitest/test_styles-matched.html
index bbfd8cafd6b8..f4e2d00f8a52 100644
--- a/devtools/server/tests/mochitest/test_styles-matched.html
+++ b/devtools/server/tests/mochitest/test_styles-matched.html
@@ -52,17 +52,23 @@ addTest(function testMatchedStyles() {
     is(matched[0].rule.href, gInspectee.defaultView.location.href,
        "Node style comes from this document");
 
-    is(matched[1].sourceText, ".inheritable-rule", "Second match comes from a rule");
-    is(matched[1].selector, ".inheritable-rule", "Second style has a selector");
-    is(matched[1].value, "15px", "Second match has the expected value");
+    is(matched[1].sourceText, ".column-rule",
+      "Second match comes from a rule");
+    is(matched[1].selector, ".column-rule",
+      "Second match comes from highest line number");
+    is(matched[1].value, "25px", "Second match comes from highest column");
     is(matched[1].status, CssLogic.STATUS.PARENT_MATCH,
-       "Second match is from the parent");
+      "Second match is from the parent");
     is(matched[1].rule.parentStyleSheet.href, null,
-       "Inline stylesheet shouldn't have an href");
+      "Inline stylesheet shouldn't have an href");
     is(matched[1].rule.parentStyleSheet.nodeHref, gInspectee.defaultView.location.href,
-       "Inline stylesheet's nodeHref should match the current document");
+      "Inline stylesheet's nodeHref should match the current document");
     ok(!matched[1].rule.parentStyleSheet.system,
-       "Inline stylesheet shouldn't be a system stylesheet.");
+      "Inline stylesheet shouldn't be a system stylesheet.");
+
+    // matched[2] is only there to test matched[1]; do not need to test
+
+    is(matched[3].value, "15px", "Third match has the expected value");
   }).then(runNextTest));
 });