diff --git a/netwerk/base/nsNetUtil.cpp b/netwerk/base/nsNetUtil.cpp
index ad0bc129ea23..e345e3363803 100644
--- a/netwerk/base/nsNetUtil.cpp
+++ b/netwerk/base/nsNetUtil.cpp
@@ -1861,6 +1861,10 @@ nsresult NS_NewURI(nsIURI** aURI, const nsACString& aSpec,
         .Finalize(aURI);
   }
 
+  if (scheme.EqualsLiteral("dweb") || scheme.EqualsLiteral("dat")) {
+    return NewStandardURI(aSpec, aCharset, aBaseURI, -1, aURI);
+  }
+
 #if defined(MOZ_THUNDERBIRD) || defined(MOZ_SUITE)
   rv = NS_NewMailnewsURI(aURI, aSpec, aCharset, aBaseURI, aIOService);
   if (rv != NS_ERROR_UNKNOWN_PROTOCOL) {
diff --git a/netwerk/test/unit/test_URIs.js b/netwerk/test/unit/test_URIs.js
index f59ba0f45bec..e61e168730db 100644
--- a/netwerk/test/unit/test_URIs.js
+++ b/netwerk/test/unit/test_URIs.js
@@ -639,6 +639,15 @@ function check_resolve() {
   Assert.equal(uri.spec, "tel::+371 27028456");
 }
 
+function test_extra_protocols() {
+  let url = gIoService.newURI("dweb://example.com/test");
+  Assert.equal(url.host, "example.com");
+  url = gIoService.newURI("dat://41f8a987cfeba80a037e51cc8357d513b62514de36f2f9b3d3eeec7a8fb3b5a5/");
+  Assert.equal(url.host, "41f8a987cfeba80a037e51cc8357d513b62514de36f2f9b3d3eeec7a8fb3b5a5");
+  url = gIoService.newURI("dat://example.com/test");
+  Assert.equal(url.host, "example.com");
+}
+
 // TEST MAIN FUNCTION
 // ------------------
 function run_test()
@@ -648,6 +657,7 @@ function run_test()
   check_schemeIsNull();
   check_mozextension_query();
   check_resolve();
+  test_extra_protocols();
 
   // UTF-8 check - From bug 622981
   // ASCII