diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index bb8921759..241e52116 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -1,4 +1,6 @@
-#include "build.hh"
+#include "derivation-goal.hh"
+#include "hook-instance.hh"
+#include "worker.hh"
 #include "builtins.hh"
 #include "builtins/buildenv.hh"
 #include "references.hh"
@@ -12,6 +14,9 @@
 #include "topo-sort.hh"
 #include "callback.hh"
 
+#include <regex>
+#include <queue>
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
@@ -140,6 +145,16 @@ DerivationGoal::~DerivationGoal()
 }
 
 
+string DerivationGoal::key()
+{
+    /* Ensure that derivations get built in order of their name,
+       i.e. a derivation named "aardvark" always comes before
+       "baboon". And substitution goals always happen before
+       derivation goals (due to "b$"). */
+    return "b$" + std::string(drvPath.name()) + "$" + worker.store.printStorePath(drvPath);
+}
+
+
 inline bool DerivationGoal::needsHashRewrite()
 {
 #if __linux__
diff --git a/src/libstore/build/goal.cc b/src/libstore/build/goal.cc
index 404a430f7..2dd7a4d37 100644
--- a/src/libstore/build/goal.cc
+++ b/src/libstore/build/goal.cc
@@ -1,4 +1,5 @@
-#include "build.hh"
+#include "goal.hh"
+#include "worker.hh"
 
 namespace nix {
 
diff --git a/src/libstore/build/hook-instance.cc b/src/libstore/build/hook-instance.cc
index a33d5e22b..0f6f580be 100644
--- a/src/libstore/build/hook-instance.cc
+++ b/src/libstore/build/hook-instance.cc
@@ -1,4 +1,5 @@
-#include "build.hh"
+#include "globals.hh"
+#include "hook-instance.hh"
 
 namespace nix {
 
diff --git a/src/libstore/build/local-store-build.cc b/src/libstore/build/local-store-build.cc
index 407979b1e..a05fb5805 100644
--- a/src/libstore/build/local-store-build.cc
+++ b/src/libstore/build/local-store-build.cc
@@ -1,4 +1,7 @@
-#include "build.hh"
+#include "machines.hh"
+#include "worker.hh"
+#include "substitution-goal.hh"
+#include "derivation-goal.hh"
 
 namespace nix {
 
diff --git a/src/libstore/build/substitution-goal.cc b/src/libstore/build/substitution-goal.cc
index dd2ce94a6..d16584f65 100644
--- a/src/libstore/build/substitution-goal.cc
+++ b/src/libstore/build/substitution-goal.cc
@@ -1,4 +1,5 @@
-#include "build.hh"
+#include "worker.hh"
+#include "substitution-goal.hh"
 #include "nar-info.hh"
 #include "finally.hh"
 
diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index 2fc9f6982..5c3fe2f57 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -1,4 +1,8 @@
-#include "build.hh"
+#include "machines.hh"
+#include "worker.hh"
+#include "substitution-goal.hh"
+#include "derivation-goal.hh"
+#include "hook-instance.hh"
 
 #include <poll.h>