diff --git a/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpCookie.java b/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpCookie.java
index 030afc0b7c70..0b7b4ba5fe41 100644
--- a/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpCookie.java
+++ b/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpCookie.java
@@ -128,7 +128,7 @@ default String getPath()
      */
     default boolean isSecure()
     {
-        return Boolean.parseBoolean(getAttributes().get(SECURE_ATTRIBUTE));
+        return isSetToNotFalse(SECURE_ATTRIBUTE);
     }
 
     /**
@@ -146,7 +146,7 @@ default SameSite getSameSite()
      */
     default boolean isHttpOnly()
     {
-        return Boolean.parseBoolean(getAttributes().get(HTTP_ONLY_ATTRIBUTE));
+        return isSetToNotFalse(HTTP_ONLY_ATTRIBUTE);
     }
 
     /**
@@ -155,8 +155,13 @@ default boolean isHttpOnly()
      */
     default boolean isPartitioned()
     {
-        String partitioned = getAttributes().get(PARTITIONED_ATTRIBUTE);
-        return partitioned != null && !StringUtil.asciiEqualsIgnoreCase("false", partitioned);
+        return isSetToNotFalse(PARTITIONED_ATTRIBUTE);
+    }
+
+    private boolean isSetToNotFalse(String attribute)
+    {
+        String value = getAttributes().get(attribute);
+        return value != null && !StringUtil.asciiEqualsIgnoreCase("false", value);
     }
 
     /**
diff --git a/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/HttpCookieUtils.java b/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/HttpCookieUtils.java
index cb54a57bd794..84750a5085ca 100644
--- a/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/HttpCookieUtils.java
+++ b/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/HttpCookieUtils.java
@@ -27,6 +27,7 @@
 import org.eclipse.jetty.util.Attributes;
 import org.eclipse.jetty.util.Index;
 import org.eclipse.jetty.util.QuotedStringTokenizer;
+import org.eclipse.jetty.util.StringUtil;
 
 /**
  * <p>Utility methods for server-side HTTP cookie handling.</p>
@@ -291,8 +292,9 @@ public static String getRFC6265SetCookie(HttpCookie httpCookie)
         {
             if (KNOWN_ATTRIBUTES.contains(e.getKey()))
                 continue;
-            builder.append("; ").append(e.getKey()).append("=");
-            builder.append(e.getValue());
+            builder.append("; ").append(e.getKey());
+            if (StringUtil.isNotBlank(e.getValue()))
+                builder.append("=").append(e.getValue());
         }
 
         return builder.toString();
diff --git a/jetty-core/jetty-server/src/test/java/org/eclipse/jetty/server/HttpCookieTest.java b/jetty-core/jetty-server/src/test/java/org/eclipse/jetty/server/HttpCookieTest.java
index 56767860f8ab..f06eb29de726 100644
--- a/jetty-core/jetty-server/src/test/java/org/eclipse/jetty/server/HttpCookieTest.java
+++ b/jetty-core/jetty-server/src/test/java/org/eclipse/jetty/server/HttpCookieTest.java
@@ -93,7 +93,7 @@ public void testMatchCookie()
     }
 
     @Test
-    public void testSetRFC2965Cookie() throws Exception
+    public void testSetRFC2965Cookie()
     {
         HttpCookie httpCookie;
 
@@ -162,10 +162,12 @@ public void testSetRFC6265Cookie()
         assertEquals("everything=value; Path=path; Domain=domain; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Secure; HttpOnly; Partitioned; SameSite=Strict", HttpCookieUtils.getRFC6265SetCookie(httpCookie));
 
         httpCookie = HttpCookie.from("everything", "value", Map.of(HttpCookie.DOMAIN_ATTRIBUTE, "domain", HttpCookie.PATH_ATTRIBUTE, "path", HttpCookie.MAX_AGE_ATTRIBUTE, Long.toString(1), HttpCookie.HTTP_ONLY_ATTRIBUTE, Boolean.toString(true), HttpCookie.SECURE_ATTRIBUTE, Boolean.toString(true), HttpCookie.SAME_SITE_ATTRIBUTE, SameSite.STRICT.getAttributeValue(), HttpCookie.PARTITIONED_ATTRIBUTE, Boolean.toString(true)));
-
         String rfc6265SetCookie = HttpCookieUtils.getRFC6265SetCookie(httpCookie);
         assertThat(rfc6265SetCookie, startsWith("everything=value; Path=path; Domain=domain; Expires="));
         assertThat(rfc6265SetCookie, endsWith(" GMT; Max-Age=1; Secure; HttpOnly; Partitioned; SameSite=Strict"));
+
+        httpCookie = HttpCookie.from("everything", "value", -1, Map.of(HttpCookie.DOMAIN_ATTRIBUTE, "domain", HttpCookie.PATH_ATTRIBUTE, "path", HttpCookie.MAX_AGE_ATTRIBUTE, Long.toString(0), HttpCookie.HTTP_ONLY_ATTRIBUTE, Boolean.toString(true), HttpCookie.SECURE_ATTRIBUTE, Boolean.toString(true), "Other", "attribute", "Single", ""));
+        assertEquals("everything=value; Path=path; Domain=domain; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Secure; HttpOnly; Other=attribute; Single", HttpCookieUtils.getRFC6265SetCookie(httpCookie));
     }
 
     public static Stream<String> rfc6265BadNameSource()