--- a/layout/style/nsCSSRules.cpp
+++ b/layout/style/nsCSSRules.cpp
@@ -2340,18 +2340,16 @@ nsCSSCounterStyleRule::SetName(const nsA
     nsIDocument* doc = GetDocument();
     MOZ_AUTO_DOC_UPDATE(doc, UPDATE_STYLE, true);
 
     mName = name;
 
     if (StyleSheet* sheet = GetStyleSheet()) {
       if (sheet->IsGecko()) {
         sheet->AsGecko()->SetModifiedByChildRule();
-      } else {
-        NS_ERROR("stylo: Dynamic change on @counter-style not yet supported");
       }
       if (doc) {
         doc->StyleRuleChanged(sheet, this);
       }
     }
   }
   return NS_OK;
 }
@@ -2389,18 +2387,16 @@ nsCSSCounterStyleRule::SetDesc(nsCSSCoun
   MOZ_AUTO_DOC_UPDATE(doc, UPDATE_STYLE, true);
 
   mValues[aDescID] = aValue;
   mGeneration++;
 
   if (StyleSheet* sheet = GetStyleSheet()) {
     if (sheet->IsGecko()) {
       sheet->AsGecko()->SetModifiedByChildRule();
-    } else {
-      NS_ERROR("stylo: Dynamic change on @counter-style not yet supported");
     }
     if (doc) {
       doc->StyleRuleChanged(sheet, this);
     }
   }
 }
 
 NS_IMETHODIMP

--- a/layout/style/test/stylo-failures.md
+++ b/layout/style/test/stylo-failures.md
@@ -48,19 +48,16 @@ to mochitest command.
 * console support bug 1352669
   * test_bug413958.html `monitorConsole` [3]
   * test_parser_diagnostics_unprintables.html [550]
 * Transition support:
   * test_transitions.html: pseudo elements [4]
   * test_transitions_and_reframes.html `pseudo-element`: bug 1366422 [4]
   * Events:
     * test_animations_event_order.html [2]
-* dynamic change on \@counter-style rule bug 1363590
-  * test_counter_style.html asserts [11]
-  * test_counter_descriptor_storage.html asserts [110]
 * symbols() function and string value on list-style-type bug 1363596
   * test_value_storage.html `symbols(` [30]
   * ... `list-style-type` [8]
   * ... `'list-style'` [18]
 * Unimplemented \@font-face descriptors:
   * test_font_face_parser.html `font-language-override`: bug 1355364 [8]
 * keyword values should be preserved in \@font-face bug 1355368
   * test_font_face_parser.html `font-weight` [4]