diff --git a/content/base/src/nsCSPParser.cpp b/content/base/src/nsCSPParser.cpp
index 718e724cf6e5..3fe7207492e8 100644
--- a/content/base/src/nsCSPParser.cpp
+++ b/content/base/src/nsCSPParser.cpp
@@ -822,13 +822,6 @@ nsCSPParser::directive()
     return;
   }
 
-  if (mCurDir.Length() < 2) {
-    const char16_t* params[] = { mCurToken.get() };
-    logWarningErrorToConsole(nsIScriptError::warningFlag, "failedToParseUnrecognizedSource",
-                             params, ArrayLength(params));
-    return;
-  }
-
   // Try to create a new CSPDirective
   nsCSPDirective* cspDir = directiveName();
   if (!cspDir) {
@@ -840,13 +833,11 @@ nsCSPParser::directive()
   nsTArray<nsCSPBaseSrc*> srcs;
   directiveValue(srcs);
 
-  // If we can not parse any srcs; it's not worth having a directive; delete and return
+  // If we can not parse any srcs; we let the source expression be the empty set ('none')
+  // see, http://www.w3.org/TR/CSP11/#source-list-parsing
   if (srcs.Length() == 0) {
-    const char16_t* params[] = { mCurToken.get() };
-    logWarningErrorToConsole(nsIScriptError::warningFlag, "failedToParseUnrecognizedSource",
-                             params, ArrayLength(params));
-    delete cspDir;
-    return;
+    nsCSPKeywordSrc *keyword = new nsCSPKeywordSrc(CSP_NONE);
+    srcs.AppendElement(keyword);
   }
 
   // Add the newly created srcs to the directive and add the directive to the policy