diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index d44dcf0ff0..5f1eb3415e 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1023,6 +1023,8 @@ void DerivationGoal::tryToBuild()
 
     } catch (BuildError & e) {
         printMsg(lvlError, e.msg());
+        outputLocks.unlock();
+        buildUser.release();
         if (printBuildTrace) {
             if (usingBuildHook)
                 printMsg(lvlError, format("@ hook-failed %1% %2% %3% %4%")
@@ -1130,6 +1132,8 @@ void DerivationGoal::buildDone()
 
     } catch (BuildError & e) {
         printMsg(lvlError, e.msg());
+        outputLocks.unlock();
+        buildUser.release();
         if (printBuildTrace) {
             /* When using a build hook, the hook will return a
                remote build failure using exit code 100.  Anything
@@ -2068,6 +2072,7 @@ void DerivationGoal::computeClosure()
        create new lock files with the same names as the old (unlinked)
        lock files. */
     outputLocks.setDeletion(true);
+    outputLocks.unlock();
 }
 
 
diff --git a/src/libstore/pathlocks.cc b/src/libstore/pathlocks.cc
index df1f0b1e38..f8753bcb66 100644
--- a/src/libstore/pathlocks.cc
+++ b/src/libstore/pathlocks.cc
@@ -203,6 +203,12 @@ void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg)
 
 
 PathLocks::~PathLocks()
+{
+    unlock();
+}
+
+
+void PathLocks::unlock()
 {
     for (list<FDPair>::iterator i = fds.begin(); i != fds.end(); i++) {
         if (deletePaths) deleteLockFilePreClose(i->second, i->first);
@@ -216,6 +222,8 @@ PathLocks::~PathLocks()
 
         debug(format("lock released on `%1%'") % i->second);
     }
+
+    fds.clear();
 }
 
 
diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh
index 8b4100028f..9898b497b9 100644
--- a/src/libstore/pathlocks.hh
+++ b/src/libstore/pathlocks.hh
@@ -36,6 +36,7 @@ public:
     void lockPaths(const PathSet & _paths,
         const string & waitMsg = "");
     ~PathLocks();
+    void unlock();
     void setDeletion(bool deletePaths);
 };