diff --git a/src/script_opt/CPP/DeclFunc.cc b/src/script_opt/CPP/DeclFunc.cc
index 75f7eeea57..9de0d02de7 100644
--- a/src/script_opt/CPP/DeclFunc.cc
+++ b/src/script_opt/CPP/DeclFunc.cc
@@ -128,7 +128,7 @@ void CPPCompile::DeclareSubclass(const FuncTypePtr& ft, const ProfileFunc* pf, c
 
     if ( lambda_ids ) {
         for ( auto& id : *lambda_ids ) {
-            auto name = lambda_names[id];
+            const auto& name = lambda_names[id];
             auto tn = FullTypeName(id->GetType());
             addl_args = addl_args + ", " + tn + " _" + name;
 
@@ -202,7 +202,7 @@ void CPPCompile::BuildLambda(const FuncTypePtr& ft, const ProfileFunc* pf, const
                              const LambdaExpr* l, const IDPList* lambda_ids) {
     // Declare the member variables for holding the captures.
     for ( auto& id : *lambda_ids ) {
-        auto name = lambda_names[id];
+        const auto& name = lambda_names[id];
         auto tn = FullTypeName(id->GetType());
         Emit("%s %s;", tn, name);
     }
diff --git a/src/script_opt/CPP/Exprs.cc b/src/script_opt/CPP/Exprs.cc
index b51e802cc2..6d6946fe49 100644
--- a/src/script_opt/CPP/Exprs.cc
+++ b/src/script_opt/CPP/Exprs.cc
@@ -1053,13 +1053,13 @@ string CPPCompile::GenDirectAssign(const ExprPtr& lhs, const string& rhs_native,
     if ( n->IsBlank() )
         return rhs_native;
 
-    auto name = IDNameStr(n);
+    const auto& name = IDNameStr(n);
 
     string gen;
 
     if ( n->IsGlobal() ) {
         const auto& t = n->GetType();
-        auto gn = globals[n->Name()];
+        const auto& gn = globals[n->Name()];
 
         if ( t->Tag() == TYPE_FUNC && t->AsFuncType()->Flavor() == FUNC_FLAVOR_EVENT ) {
             gen = string("set_event__CPP(") + gn + ", " + rhs_val_ptr + ", " + gn + "_ev)";
diff --git a/src/script_opt/CPP/Stmts.cc b/src/script_opt/CPP/Stmts.cc
index ace13e4e24..0df91317a2 100644
--- a/src/script_opt/CPP/Stmts.cc
+++ b/src/script_opt/CPP/Stmts.cc
@@ -320,7 +320,7 @@ void CPPCompile::GenWhenStmt(const WhenInfo* wi, const std::string& when_lambda,
                              vector<string> local_aggrs) {
     auto is_return = wi->IsReturn() ? "true" : "false";
     auto timeout = wi->TimeoutExpr();
-    auto timeout_val = timeout ? GenExpr(timeout, GEN_NATIVE) : "-1.0";
+    const auto& timeout_val = timeout ? GenExpr(timeout, GEN_NATIVE) : "-1.0";
 
     Emit("{ // begin a new scope for internal variables");
 
diff --git a/src/script_opt/ScriptOpt.cc b/src/script_opt/ScriptOpt.cc
index c9c5533ca7..9daf28cbc9 100644
--- a/src/script_opt/ScriptOpt.cc
+++ b/src/script_opt/ScriptOpt.cc
@@ -519,7 +519,7 @@ static void analyze_scripts_for_ZAM(std::shared_ptr<ProfileFuncs> pfs) {
             if ( g->GetType()->Tag() != TYPE_FUNC )
                 continue;
 
-            auto v = g->GetVal();
+            const auto& v = g->GetVal();
             if ( v )
                 func_used_indirectly.insert(v->AsFunc());
         }
diff --git a/src/script_opt/ZAM/Stmt.cc b/src/script_opt/ZAM/Stmt.cc
index a7127cd565..53cf43479b 100644
--- a/src/script_opt/ZAM/Stmt.cc
+++ b/src/script_opt/ZAM/Stmt.cc
@@ -941,8 +941,8 @@ const ZAMStmt ZAMCompiler::CompileReturn(const ReturnStmt* r) {
 const ZAMStmt ZAMCompiler::CompileCatchReturn(const CatchReturnStmt* cr) {
     retvars.push_back(cr->RetVar());
 
-    auto hold_func = ZAM::curr_func;
-    auto hold_loc = ZAM::curr_loc;
+    const auto& hold_func = ZAM::curr_func;
+    const auto& hold_loc = ZAM::curr_loc;
 
     ZAM::curr_func = cr->Func()->GetName();