--- a/dom/security/test/cors/test_CrossSiteXHR_cache.html
+++ b/dom/security/test/cors/test_CrossSiteXHR_cache.html
@@ -58,26 +58,41 @@ function* runTest() {
              headers: { "x-my-header": "myValue",
                         "y-my-header": "second" },
            },
            { pass: 1,
              method: "GET",
              headers: { "y-my-header": "hello" },
              allowHeaders: "y-my-header",
            },
-           { pass: 0,
+           { pass: 1,
              method: "GET",
              headers: { "y-my-header": "hello" },
            },
            { pass: 1,
              method: "GET",
              headers: { "y-my-header": "hello" },
              allowHeaders: "y-my-header,x-my-header",
              cacheTime: 3600,
            },
+           { pass: 0,
+             method: "GET",
+             headers: { "x-my-header": "myValue",
+                        "y-my-header": "second" },
+           },
+           { newTest: "*******" },
+           { pass: 1,
+             method: "GET",
+             headers: { "y-my-header": "hello" },
+             allowHeaders: "y-my-header,x-my-header",
+           },
+           { pass: 1,
+             method: "GET",
+             headers: { "y-my-header": "hello" },
+           },
            { pass: 1,
              method: "GET",
              headers: { "x-my-header": "myValue",
                         "y-my-header": "second" },
            },
            { newTest: "*******" },
            { pass: 0,
              method: "GET",
@@ -219,17 +234,17 @@ function* runTest() {
            },
            { pass: 0,
              method: "PATCH",
            },
            { pass: 1,
              method: "PATCH",
              allowMethods: "PATCH",
            },
-           { pass: 0,
+           { pass: 1,
              method: "PATCH",
            },
            { pass: 1,
              method: "PATCH",
              allowMethods: "PATCH",
              cacheTime: 3600,
            },
            { pass: 1,
@@ -237,16 +252,25 @@ function* runTest() {
            },
            { pass: 0,
              method: "DELETE",
            },
            { pass: 0,
              method: "PUT",
            },
            { newTest: "*******" },
+           { pass: 1,
+             method: "PATCH",
+             allowMethods: "PATCH",
+             cacheTime: 3600,
+           },
+           { pass: 1,
+             method: "PATCH",
+           },
+           { newTest: "*******" },
            { pass: 0,
              method: "DELETE",
            },
            { pass: 1,
              method: "DELETE",
              allowMethods: "DELETE",
              cacheTime: 2
            },

--- a/netwerk/protocol/http/nsCORSListenerProxy.cpp
+++ b/netwerk/protocol/http/nsCORSListenerProxy.cpp
@@ -45,16 +45,18 @@
 #include "nsQueryObject.h"
 #include "mozilla/StaticPrefs_network.h"
 #include <algorithm>
 
 using namespace mozilla;
 using namespace mozilla::net;
 
 #define PREFLIGHT_CACHE_SIZE 100
+// 5 seconds is chosen to be compatible with Chromium.
+#define PREFLIGHT_DEFAULT_EXPIRY_SECONDS 5
 
 static void LogBlockedRequest(nsIRequest* aRequest, const char* aProperty,
                               const char16_t* aParam, uint32_t aBlockingReason,
                               nsIHttpChannel* aCreatingChannel) {
   nsresult rv = NS_OK;
 
   nsCOMPtr<nsIChannel> channel = do_QueryInterface(aRequest);
 
@@ -1107,37 +1109,37 @@ NS_IMPL_ISUPPORTS(nsCORSPreflightListene
                   nsIChannelEventSink)
 
 void nsCORSPreflightListener::AddResultToCache(nsIRequest* aRequest) {
   nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(aRequest);
   NS_ASSERTION(http, "Request was not http");
 
   // The "Access-Control-Max-Age" header should return an age in seconds.
   nsAutoCString headerVal;
+  uint32_t age = 0;
   Unused << http->GetResponseHeader(
       NS_LITERAL_CSTRING("Access-Control-Max-Age"), headerVal);
   if (headerVal.IsEmpty()) {
-    return;
-  }
-
-  // Sanitize the string. We only allow 'delta-seconds' as specified by
-  // http://dev.w3.org/2006/waf/access-control (digits 0-9 with no leading or
-  // trailing non-whitespace characters).
-  uint32_t age = 0;
-  nsACString::const_char_iterator iter, end;
-  headerVal.BeginReading(iter);
-  headerVal.EndReading(end);
-  while (iter != end) {
-    if (*iter < '0' || *iter > '9') {
-      return;
+    age = PREFLIGHT_DEFAULT_EXPIRY_SECONDS;
+  } else {
+    // Sanitize the string. We only allow 'delta-seconds' as specified by
+    // http://dev.w3.org/2006/waf/access-control (digits 0-9 with no leading or
+    // trailing non-whitespace characters).
+    nsACString::const_char_iterator iter, end;
+    headerVal.BeginReading(iter);
+    headerVal.EndReading(end);
+    while (iter != end) {
+      if (*iter < '0' || *iter > '9') {
+        return;
+      }
+      age = age * 10 + (*iter - '0');
+      // Cap at 24 hours. This also avoids overflow
+      age = std::min(age, 86400U);
+      ++iter;
     }
-    age = age * 10 + (*iter - '0');
-    // Cap at 24 hours. This also avoids overflow
-    age = std::min(age, 86400U);
-    ++iter;
   }
 
   if (!age || !EnsurePreflightCache()) {
     return;
   }
 
   // String seems fine, go ahead and cache.
   // Note that we have already checked that these headers follow the correct

deleted file mode 100644
--- a/testing/web-platform/meta/cors/preflight-cache.htm.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[preflight-cache.htm]
-  [preflight for x-print should be cached]
-    expected: FAIL
-

--- a/testing/web-platform/tests/cors/preflight-cache.htm
+++ b/testing/web-platform/tests/cors/preflight-cache.htm
@@ -59,16 +59,25 @@ test(function() {
     did_preflight(false, client, {token: id})
 },
 'preflight for x-print should be cached')
 
 test(function() {
     var time = new Date().getTime()
     var client = new XMLHttpRequest()
 
+    var id = did_preflight(true, client, {extra:'max_age='})
+    did_preflight(false, client, {extra:'max_age=', token: id})
+},
+'age = blank, should be cached')
+
+test(function() {
+    var time = new Date().getTime()
+    var client = new XMLHttpRequest()
+
     var id = did_preflight(true, client, {extra:'max_age=0'})
     did_preflight(true, client, {extra:'max_age=0', token: id})
 },
 'age = 0, should not be cached')
 
 test(function() {
     var time = new Date().getTime()
     var client = new XMLHttpRequest()