diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 8ec45ef8060..6626cfde97b 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1448,6 +1448,10 @@ pref("network.http.enforce-framing.soft", true);
 // See http://www.w3.org/TR/web-packaging/#streamable-package-format
 pref("network.http.enable-packaged-apps", false);
 
+// Enable this to bring in the signature verification if the signature exists.
+// Set to false if you don't need the signed packaged web app support (i.e. NSec).
+pref("network.http.packaged-signed-apps-enabled", false);
+
 // Enable this pref to skip verification process. The packaged app
 // will be considered signed no matter the package has a valid/invalid
 // signature or no signature.
diff --git a/netwerk/protocol/http/PackagedAppService.cpp b/netwerk/protocol/http/PackagedAppService.cpp
index 25341fc6a18..df660ad472b 100644
--- a/netwerk/protocol/http/PackagedAppService.cpp
+++ b/netwerk/protocol/http/PackagedAppService.cpp
@@ -479,6 +479,12 @@ PackagedAppService::PackagedAppDownloader::OnStartRequest(nsIRequest *aRequest,
   NS_WARN_IF(NS_FAILED(rv));
 
   EnsureVerifier(aRequest);
+
+  if (!mVerifier->WouldVerify()) {
+    // It means there's no signature or the signed app is disabled.
+    return NS_OK;
+  }
+
   mVerifier->OnStartRequest(nullptr, uri);
 
   // Since the header is considered as a part of the streaming data,
@@ -640,7 +646,7 @@ PackagedAppService::PackagedAppDownloader::OnStopRequest(nsIRequest *aRequest,
       // Chances to get here:
       //   1) Very likely the package has been cached or
       //   2) Less likely the package is malformed.
-      if (!mVerifier) {
+      if (!mVerifier || !mVerifier->WouldVerify()) {
         FinalizeDownload(aStatusCode);
       } else {
         // We've got a broken last part and some resources might be still
@@ -676,6 +682,12 @@ PackagedAppService::PackagedAppDownloader::OnStopRequest(nsIRequest *aRequest,
   nsRefPtr<ResourceCacheInfo> info =
     new ResourceCacheInfo(uri, entry, aStatusCode, lastPart);
 
+  if (!mVerifier->WouldVerify()) {
+    // No manifest at all. Everything is simply a resource.
+    OnResourceVerified(info, true);
+    return NS_OK;
+  }
+
   mVerifier->OnStopRequest(nullptr, info, aStatusCode);
 
   return NS_OK;
@@ -704,6 +716,11 @@ PackagedAppService::PackagedAppDownloader::ConsumeData(nsIInputStream *aStream,
 
   self->mWriter->ConsumeData(aFromRawSegment, aCount, aWriteCount);
 
+  if (!self->mVerifier->WouldVerify()) {
+    // No signature or signed app support is disabled.
+    return NS_OK;
+  }
+
   if (self->mProcessingFirstRequest) {
     // mProcessingFirstRequest will be set to false on the first OnStopRequest.
     self->mManifestContent.Append(aFromRawSegment, aCount);
diff --git a/netwerk/protocol/http/PackagedAppVerifier.cpp b/netwerk/protocol/http/PackagedAppVerifier.cpp
index b30bb71ea89..d823b29dcd2 100644
--- a/netwerk/protocol/http/PackagedAppVerifier.cpp
+++ b/netwerk/protocol/http/PackagedAppVerifier.cpp
@@ -22,6 +22,7 @@ static const short kResourceHashType = nsICryptoHash::SHA256;
 // If it's true, all the verification will be skipped and the package will
 // be treated signed.
 static bool gDeveloperMode = false;
+static bool gSignedAppEnabled = false;
 
 namespace mozilla {
 namespace net {
@@ -69,6 +70,8 @@ NS_IMETHODIMP PackagedAppVerifier::Init(nsIPackagedAppVerifierListener* aListene
   if (!onceThru) {
     Preferences::AddBoolVarCache(&gDeveloperMode,
                                  "network.http.packaged-apps-developer-mode", false);
+    Preferences::AddBoolVarCache(&gSignedAppEnabled,
+                                 "network.http.packaged-signed-apps-enabled", false);
     onceThru = true;
   }
 
@@ -418,6 +421,12 @@ PackagedAppVerifier::SetHasBrokenLastPart(nsresult aStatusCode)
   mPendingResourceCacheInfoList.insertBack(info);
 }
 
+bool
+PackagedAppVerifier::WouldVerify() const
+{
+  return gSignedAppEnabled && !mSignature.IsEmpty();
+}
+
 //---------------------------------------------------------------
 // nsIPackagedAppVerifier.
 //---------------------------------------------------------------
diff --git a/netwerk/protocol/http/PackagedAppVerifier.h b/netwerk/protocol/http/PackagedAppVerifier.h
index b733bc46cbe..4241bbeba4b 100644
--- a/netwerk/protocol/http/PackagedAppVerifier.h
+++ b/netwerk/protocol/http/PackagedAppVerifier.h
@@ -114,6 +114,8 @@ public:
     return mPackageOrigin;
   }
 
+  bool WouldVerify() const;
+
   static const char* kSignedPakOriginMetadataKey;
 
 private:
diff --git a/netwerk/test/mochitests/test_signed_web_packaged_app.html b/netwerk/test/mochitests/test_signed_web_packaged_app.html
index 7eae7b89568..b1d0b6eda2c 100644
--- a/netwerk/test/mochitests/test_signed_web_packaged_app.html
+++ b/netwerk/test/mochitests/test_signed_web_packaged_app.html
@@ -22,6 +22,7 @@ var Cr = SpecialPowers.Cr;
 SpecialPowers.pushPrefEnv(
   { "set": [["network.http.enable-packaged-apps", true],
             ["network.http.packaged-apps-developer-mode", true],
+            ["network.http.packaged-signed-apps-enabled", true],
             ["dom.ipc.processPriorityManager.testMode", true],
             ["dom.ipc.processPriorityManager.enabled", true],
             ["dom.ipc.tabs.disabled", false],
diff --git a/netwerk/test/unit/test_packaged_app_channel.js b/netwerk/test/unit/test_packaged_app_channel.js
index 171f48f8140..6c361f06ec6 100644
--- a/netwerk/test/unit/test_packaged_app_channel.js
+++ b/netwerk/test/unit/test_packaged_app_channel.js
@@ -118,6 +118,7 @@ function contentHandlerWithSignature(metadata, response)
 var httpserver = null;
 var originalPref = false;
 var originalDevMode = false;
+var originalSignedAppEnabled = false;
 
 function run_test()
 {
@@ -131,8 +132,10 @@ function run_test()
   // Enable the feature and save the original pref value
   originalPref = Services.prefs.getBoolPref("network.http.enable-packaged-apps");
   originalDevMode = Services.prefs.getBoolPref("network.http.packaged-apps-developer-mode");
+  originalSignedAppEnabled = Services.prefs.getBoolPref("network.http.packaged-signed-apps-enabled");
   Services.prefs.setBoolPref("network.http.enable-packaged-apps", true);
   Services.prefs.setBoolPref("network.http.packaged-apps-developer-mode", false);
+  Services.prefs.setBoolPref("network.http.packaged-signed-apps-enabled", true);
   do_register_cleanup(reset_pref);
 
   add_test(test_channel);
@@ -206,4 +209,5 @@ function reset_pref() {
   // Set the pref to its original value
   Services.prefs.setBoolPref("network.http.enable-packaged-apps", originalPref);
   Services.prefs.setBoolPref("network.http.packaged-apps-developer-mode", originalDevMode);
+  Services.prefs.setBoolPref("network.http.packaged-signed-apps-enabled", originalSignedAppEnabled);
 }
diff --git a/netwerk/test/unit/test_packaged_app_service.js b/netwerk/test/unit/test_packaged_app_service.js
index bebb875890f..3014ff9dd2c 100644
--- a/netwerk/test/unit/test_packaged_app_service.js
+++ b/netwerk/test/unit/test_packaged_app_service.js
@@ -155,12 +155,15 @@ function run_test()
   // TODO: To be removed in Bug 1178518.
   do_register_cleanup(function() {
     gPrefs.clearUserPref("network.http.packaged-apps-developer-mode");
+    gPrefs.clearUserPref("network.http.packaged-signed-apps-enabled");
   });
 
   paservice = Cc["@mozilla.org/network/packaged-app-service;1"]
                      .getService(Ci.nsIPackagedAppService);
   ok(!!paservice, "test service exists");
 
+  gPrefs.setBoolPref("network.http.packaged-signed-apps-enabled", true);
+
   add_test(test_bad_args);
 
   add_test(test_callback_gets_called);