1 files changed, 2 insertions, 0 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index ab8923bbd..36436d7eb 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1914,6 +1914,8 @@ void DerivationGoal::startBuilder()
     builderOut.create();
 
     /* Fork a child to build the package. */
+    ProcessOptions options;
+    options.allowVfork = !buildUser.enabled();
     pid = startProcess([&]() {
         runChild();
     });