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 edb496024..1dd11160f 100644
--- a/src/libstore/include/nix/store/build/derivation-building-goal.hh
+++ b/src/libstore/include/nix/store/build/derivation-building-goal.hh
@@ -29,8 +29,7 @@ typedef enum { rpAccept, rpDecline, rpPostpone } HookReply;
  */
 struct DerivationBuildingGoal : public Goal
 {
-    DerivationBuildingGoal(
-        const StorePath & drvPath, const Derivation & drv, Worker & worker, BuildMode buildMode = bmNormal);
+    DerivationBuildingGoal(const StorePath & drvPath, const Derivation & drv, Worker & worker, BuildMode buildMode);
     ~DerivationBuildingGoal();
 
 private:
diff --git a/src/libstore/include/nix/store/build/derivation-goal.hh b/src/libstore/include/nix/store/build/derivation-goal.hh
index e05bf1c0b..13369d889 100644
--- a/src/libstore/include/nix/store/build/derivation-goal.hh
+++ b/src/libstore/include/nix/store/build/derivation-goal.hh
@@ -45,7 +45,7 @@ struct DerivationGoal : public Goal
         const Derivation & drv,
         const OutputName & wantedOutput,
         Worker & worker,
-        BuildMode buildMode = bmNormal);
+        BuildMode buildMode);
     ~DerivationGoal() = default;
 
     void timedOut(Error && ex) override
diff --git a/src/libstore/include/nix/store/build/derivation-resolution-goal.hh b/src/libstore/include/nix/store/build/derivation-resolution-goal.hh
index a284843f0..fb4c2a346 100644
--- a/src/libstore/include/nix/store/build/derivation-resolution-goal.hh
+++ b/src/libstore/include/nix/store/build/derivation-resolution-goal.hh
@@ -35,8 +35,7 @@ struct BuilderFailureError;
  */
 struct DerivationResolutionGoal : public Goal
 {
-    DerivationResolutionGoal(
-        const StorePath & drvPath, const Derivation & drv, Worker & worker, BuildMode buildMode = bmNormal);
+    DerivationResolutionGoal(const StorePath & drvPath, const Derivation & drv, Worker & worker, BuildMode buildMode);
 
     /**
      * If the derivation needed to be resolved, this is resulting
diff --git a/src/libstore/include/nix/store/build/worker.hh b/src/libstore/include/nix/store/build/worker.hh
index 9660d66b2..542e3ff33 100644
--- a/src/libstore/include/nix/store/build/worker.hh
+++ b/src/libstore/include/nix/store/build/worker.hh
@@ -210,32 +210,26 @@ private:
     std::shared_ptr<G> initGoalIfNeeded(std::weak_ptr<G> & goal_weak, Args &&... args);
 
     std::shared_ptr<DerivationTrampolineGoal> makeDerivationTrampolineGoal(
-        ref<const SingleDerivedPath> drvReq, const OutputsSpec & wantedOutputs, BuildMode buildMode = bmNormal);
+        ref<const SingleDerivedPath> drvReq, const OutputsSpec & wantedOutputs, BuildMode buildMode);
 
 public:
     std::shared_ptr<DerivationTrampolineGoal> makeDerivationTrampolineGoal(
-        const StorePath & drvPath,
-        const OutputsSpec & wantedOutputs,
-        const Derivation & drv,
-        BuildMode buildMode = bmNormal);
+        const StorePath & drvPath, const OutputsSpec & wantedOutputs, const Derivation & drv, BuildMode buildMode);
 
     std::shared_ptr<DerivationGoal> makeDerivationGoal(
-        const StorePath & drvPath,
-        const Derivation & drv,
-        const OutputName & wantedOutput,
-        BuildMode buildMode = bmNormal);
+        const StorePath & drvPath, const Derivation & drv, const OutputName & wantedOutput, BuildMode buildMode);
 
     /**
      * @ref DerivationResolutionGoal "derivation resolution goal"
      */
     std::shared_ptr<DerivationResolutionGoal>
-    makeDerivationResolutionGoal(const StorePath & drvPath, const Derivation & drv, BuildMode buildMode = bmNormal);
+    makeDerivationResolutionGoal(const StorePath & drvPath, const Derivation & drv, BuildMode buildMode);
 
     /**
      * @ref DerivationBuildingGoal "derivation building goal"
      */
     std::shared_ptr<DerivationBuildingGoal>
-    makeDerivationBuildingGoal(const StorePath & drvPath, const Derivation & drv, BuildMode buildMode = bmNormal);
+    makeDerivationBuildingGoal(const StorePath & drvPath, const Derivation & drv, BuildMode buildMode);
 
     /**
      * @ref PathSubstitutionGoal "substitution goal"