diff --git a/README.md b/README.md
index facb9ebb..63770060 100644
--- a/README.md
+++ b/README.md
@@ -301,6 +301,8 @@ Configuration items are:
 
 ## News and noteworthy
  
+* v6.3.3 - 2021-05-31
+    * Allow unknown rules inside `@media` rules ([issue #67](https://github.com/phax/ph-css/issues/67)) - thanks @yinkwok-ys
 * v6.3.2 - 2021-05-25
     * Fixed an error with the negation parameters ([issue #66](https://github.com/phax/ph-css/issues/66)) - thanks @rockwotj
 * v6.3.1 - 2021-05-02
diff --git a/ph-css/src/test/java/com/helger/css/reader/CSSReader30SpecialFuncTest.java b/ph-css/src/test/java/com/helger/css/reader/CSSReader30SpecialFuncTest.java
index b31c9ec5..c50f9e4d 100644
--- a/ph-css/src/test/java/com/helger/css/reader/CSSReader30SpecialFuncTest.java
+++ b/ph-css/src/test/java/com/helger/css/reader/CSSReader30SpecialFuncTest.java
@@ -37,7 +37,6 @@
 import com.helger.css.decl.CSSExpressionMemberMath;
 import com.helger.css.decl.CSSExpressionMemberTermSimple;
 import com.helger.css.decl.CSSExpressionMemberTermURI;
-import com.helger.css.decl.CSSMediaRule;
 import com.helger.css.decl.CSSPageMarginBlock;
 import com.helger.css.decl.CSSPageRule;
 import com.helger.css.decl.CSSStyleRule;
@@ -358,32 +357,6 @@ public void testReadSingleLineComments ()
     assertEquals (1, aCSS.getStyleRuleAtIndex (12).getDeclarationCount ());
   }
 
-  @Test
-  public void testIssue67 ()
-  {
-    final String sCSS = "@media (max-width: 959px) {\r\n" +
-                        "  @-moz-document url-prefix() {\r\n" +
-                        "    .test-class {\r\n" +
-                        "      height: 1vh;\r\n" +
-                        "      visibility: collapse;\r\n" +
-                        "    }\r\n" +
-                        "  }\r\n" +
-                        "}\r\n" +
-                        "\r\n" +
-                        "@-moz-anything {}";
-    final CascadingStyleSheet aCSS = CSSReader.readFromString (sCSS, ECSSVersion.LATEST);
-    assertNotNull (aCSS);
-    assertEquals (2, aCSS.getRuleCount ());
-    assertEquals (1, aCSS.getMediaRuleCount ());
-    assertEquals (1, aCSS.getUnknownRuleCount ());
-
-    final CSSMediaRule aMR = aCSS.getMediaRuleAtIndex (0);
-    assertNotNull (aMR);
-
-    assertEquals (1, aMR.getRuleCount ());
-    assertEquals (1, aMR.getUnknownRuleCount ());
-  }
-
   @Test
   public void testReadFootnote ()
   {
diff --git a/ph-css/src/test/java/com/helger/css/supplementary/issues/Issue67Test.java b/ph-css/src/test/java/com/helger/css/supplementary/issues/Issue67Test.java
new file mode 100644
index 00000000..bb936563
--- /dev/null
+++ b/ph-css/src/test/java/com/helger/css/supplementary/issues/Issue67Test.java
@@ -0,0 +1,61 @@
+/**
+ * Copyright (C) 2014-2021 Philip Helger (www.helger.com)
+ * philip[at]helger[dot]com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.helger.css.supplementary.issues;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+
+import com.helger.css.ECSSVersion;
+import com.helger.css.decl.CSSMediaRule;
+import com.helger.css.decl.CascadingStyleSheet;
+import com.helger.css.reader.CSSReader;
+
+/**
+ * Test for issue 61: https://github.com/phax/ph-css/issues/67
+ *
+ * @author Philip Helger
+ */
+public final class Issue67Test
+{
+  @Test
+  public void testIssue67 ()
+  {
+    final String sCSS = "@media (max-width: 959px) {\r\n" +
+                        "  @-moz-document url-prefix() {\r\n" +
+                        "    .test-class {\r\n" +
+                        "      height: 1vh;\r\n" +
+                        "      visibility: collapse;\r\n" +
+                        "    }\r\n" +
+                        "  }\r\n" +
+                        "}\r\n" +
+                        "\r\n" +
+                        "@-moz-anything {}";
+    final CascadingStyleSheet aCSS = CSSReader.readFromString (sCSS, ECSSVersion.LATEST);
+    assertNotNull (aCSS);
+    assertEquals (2, aCSS.getRuleCount ());
+    assertEquals (1, aCSS.getMediaRuleCount ());
+    assertEquals (1, aCSS.getUnknownRuleCount ());
+
+    final CSSMediaRule aMR = aCSS.getMediaRuleAtIndex (0);
+    assertNotNull (aMR);
+
+    assertEquals (1, aMR.getRuleCount ());
+    assertEquals (1, aMR.getUnknownRuleCount ());
+  }
+}