diff --git a/interface/Combine.h b/interface/Combine.h
index 5aea6a5e41a..0bf0a07d902 100644
--- a/interface/Combine.h
+++ b/interface/Combine.h
@@ -32,6 +32,7 @@ extern bool bypassFrequentistFit_;
 extern  std::string setPhysicsModelParameterExpression_;
 extern  std::string setPhysicsModelParameterRangeExpression_;
 extern  std::string defineBackgroundOnlyModelParameterExpression_;
+extern  std::string nllBackend_;
 
 namespace { 
     struct ToCleanUp {
diff --git a/src/Combine.cc b/src/Combine.cc
index 4cf64dd0974..5f083c22c49 100644
--- a/src/Combine.cc
+++ b/src/Combine.cc
@@ -91,6 +91,7 @@ TTree *Combine::tree_ = 0;
 std::string setPhysicsModelParameterExpression_ = "";
 std::string setPhysicsModelParameterRangeExpression_ = "";
 std::string defineBackgroundOnlyModelParameterExpression_ = "";
+std::string nllBackend_ = "combine";
 
 std::string Combine::trackParametersNameString_="";
 std::string Combine::trackErrorsNameString_="";
diff --git a/src/RooSimultaneousOpt.cc b/src/RooSimultaneousOpt.cc
index f689b4af999..de51640ca81 100644
--- a/src/RooSimultaneousOpt.cc
+++ b/src/RooSimultaneousOpt.cc
@@ -2,6 +2,8 @@
 #include "../interface/CachingNLL.h"
 #include <RooCmdConfig.h>
 
+extern  std::string nllBackend_;
+
 #if ROOT_VERSION_CODE < ROOT_VERSION(6,30,0)
 RooAbsReal* 
 RooSimultaneousOpt::createNLL(RooAbsData& data, const RooLinkedList& cmdList) 
@@ -10,6 +12,16 @@ std::unique_ptr<RooAbsReal>
 RooSimultaneousOpt::createNLLImpl(RooAbsData& data, const RooLinkedList& cmdList) 
 #endif
 {
+    if (nllBackend_ != "combine") {
+        RooLinkedList cmdListCopy{cmdList};
+        // Set the RooFit::EvalBackend() of RooFit to what the nllBackend_ in
+        // combine is set.
+#if ROOT_VERSION_CODE >= ROOT_VERSION(6,30,0)
+        RooCmdArg evalBackendArg{RooFit::EvalBackend(nllBackend_)};
+        cmdListCopy.Add(&evalBackendArg);
+#endif
+        return RooSimultaneous::createNLLImpl(data, cmdListCopy);
+    }
     RooCmdConfig pc(Form("RooSimultaneousOpt::createNLL(%s)",GetName())) ;
     pc.defineSet("cPars","Constrain",0,0);
     RooArgSet *cPars = pc.getSet("cPars");