diff --git a/src/libstore/include/nix/store/build/derivation-building-goal.hh b/src/libstore/include/nix/store/build/derivation-building-goal.hh
index b16a1300c..95949649c 100644
--- a/src/libstore/include/nix/store/build/derivation-building-goal.hh
+++ b/src/libstore/include/nix/store/build/derivation-building-goal.hh
@@ -174,8 +174,6 @@ struct DerivationBuildingGoal : public Goal
 
     void appendLogTailErrorMsg(std::string & msg);
 
-    StorePathSet exportReferences(const StorePathSet & storePaths);
-
     JobCategory jobCategory() const override
     {
         return JobCategory::Build;