diff --git a/dom/workers/ScriptLoader.cpp b/dom/workers/ScriptLoader.cpp
index 3295160af3..6b036b3cff 100644
--- a/dom/workers/ScriptLoader.cpp
+++ b/dom/workers/ScriptLoader.cpp
@@ -1204,48 +1204,9 @@ private:
       // We did inherit CSP in bug 1223647. If we do not already have a CSP, we
       // should get it from the HTTP headers on the worker script.
       if (!mWorkerPrivate->GetCSP() && CSPService::sCSPEnabled) {
-        NS_ConvertASCIItoUTF16 cspHeaderValue(tCspHeaderValue);
-        NS_ConvertASCIItoUTF16 cspROHeaderValue(tCspROHeaderValue);
-
-        nsIPrincipal* principal = mWorkerPrivate->GetPrincipal();
-        MOZ_ASSERT(principal, "Should not be null");
-
-        nsCOMPtr<nsIContentSecurityPolicy> csp;
-        rv = principal->EnsureCSP(nullptr, getter_AddRefs(csp));
-
-        if (csp) {
-          // If there's a CSP header, apply it.
-          if (!cspHeaderValue.IsEmpty()) {
-            rv = CSP_AppendCSPFromHeader(csp, cspHeaderValue, false);
-            NS_ENSURE_SUCCESS(rv, rv);
-          }
-          // If there's a report-only CSP header, apply it.
-          if (!cspROHeaderValue.IsEmpty()) {
-            rv = CSP_AppendCSPFromHeader(csp, cspROHeaderValue, true);
-            NS_ENSURE_SUCCESS(rv, rv);
-          }
-
-          // Set evalAllowed, default value is set in GetAllowsEval
-          bool evalAllowed = false;
-          bool reportEvalViolations = false;
-          rv = csp->GetAllowsEval(&reportEvalViolations, &evalAllowed);
-          NS_ENSURE_SUCCESS(rv, rv);
-
-          mWorkerPrivate->SetCSP(csp);
-          mWorkerPrivate->SetEvalAllowed(evalAllowed);
-          mWorkerPrivate->SetReportCSPViolations(reportEvalViolations);
-
-          // Set ReferrerPolicy, default value is set in GetReferrerPolicy
-          bool hasReferrerPolicy = false;
-          uint32_t rp = mozilla::net::RP_Default;
-          rv = csp->GetReferrerPolicy(&rp, &hasReferrerPolicy);
-          NS_ENSURE_SUCCESS(rv, rv);
-
-
-          if (hasReferrerPolicy) { //FIXME bug 1307366: move RP out of CSP code
-            mWorkerPrivate->SetReferrerPolicy(static_cast<net::ReferrerPolicy>(rp));
-          }
-        }
+        rv = mWorkerPrivate->SetCSPFromHeaderValues(tCspHeaderValue,
+                                                    tCspROHeaderValue);
+        NS_ENSURE_SUCCESS(rv, rv);
       }
       if (parent) {
         // XHR Params Allowed
diff --git a/dom/workers/WorkerPrivate.cpp b/dom/workers/WorkerPrivate.cpp
index 5e211c1085..01a8368c81 100644
--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -58,6 +58,7 @@
 #include "mozilla/dom/MessageEventBinding.h"
 #include "mozilla/dom/MessagePort.h"
 #include "mozilla/dom/MessagePortBinding.h"
+#include "mozilla/dom/nsCSPUtils.h"
 #include "mozilla/dom/Performance.h"
 #include "mozilla/dom/PMessagePort.h"
 #include "mozilla/dom/Promise.h"
@@ -2382,6 +2383,56 @@ WorkerPrivateParent<Derived>::GetDocument() const
   return nullptr;
 }
 
+template <class Derived>
+nsresult
+WorkerPrivateParent<Derived>::SetCSPFromHeaderValues(const nsACString& aCSPHeaderValue,
+                                                     const nsACString& aCSPReportOnlyHeaderValue)
+{
+  AssertIsOnMainThread();
+  MOZ_DIAGNOSTIC_ASSERT(!mLoadInfo.mCSP);
+
+  NS_ConvertASCIItoUTF16 cspHeaderValue(aCSPHeaderValue);
+  NS_ConvertASCIItoUTF16 cspROHeaderValue(aCSPReportOnlyHeaderValue);
+
+  nsCOMPtr<nsIContentSecurityPolicy> csp;
+  nsresult rv = mLoadInfo.mPrincipal->EnsureCSP(nullptr, getter_AddRefs(csp));
+  if (!csp) {
+    return NS_OK;
+  }
+
+  // If there's a CSP header, apply it.
+  if (!cspHeaderValue.IsEmpty()) {
+    rv = CSP_AppendCSPFromHeader(csp, cspHeaderValue, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  // If there's a report-only CSP header, apply it.
+  if (!cspROHeaderValue.IsEmpty()) {
+    rv = CSP_AppendCSPFromHeader(csp, cspROHeaderValue, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // Set evalAllowed, default value is set in GetAllowsEval
+  bool evalAllowed = false;
+  bool reportEvalViolations = false;
+  rv = csp->GetAllowsEval(&reportEvalViolations, &evalAllowed);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Set ReferrerPolicy, default value is set in GetReferrerPolicy
+  bool hasReferrerPolicy = false;
+  uint32_t rp = mozilla::net::RP_Unset;
+  rv = csp->GetReferrerPolicy(&rp, &hasReferrerPolicy);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mLoadInfo.mCSP = csp;
+  mLoadInfo.mEvalAllowed = evalAllowed;
+  mLoadInfo.mReportCSPViolations = reportEvalViolations;
+
+  if (hasReferrerPolicy) {
+    mLoadInfo.mReferrerPolicy = static_cast<net::ReferrerPolicy>(rp);
+  }
+
+  return NS_OK;
+}
 
 // Can't use NS_IMPL_CYCLE_COLLECTION_CLASS(WorkerPrivateParent) because of the
 // templates.
diff --git a/dom/workers/WorkerPrivate.h b/dom/workers/WorkerPrivate.h
index 26afecb69b..b82e994028 100644
--- a/dom/workers/WorkerPrivate.h
+++ b/dom/workers/WorkerPrivate.h
@@ -701,6 +701,10 @@ public:
     mLoadInfo.mCSP = aCSP;
   }
 
+  nsresult
+  SetCSPFromHeaderValues(const nsACString& aCSPHeaderValue,
+                         const nsACString& aCSPReportOnlyHeaderValue);
+
   net::ReferrerPolicy
   GetReferrerPolicy() const
   {