diff --git a/doc/manual/troubleshooting.xml b/doc/manual/troubleshooting.xml
index c0add7fdda..e1e6c08c86 100644
--- a/doc/manual/troubleshooting.xml
+++ b/doc/manual/troubleshooting.xml
@@ -43,8 +43,9 @@ Berkeley DB error: file validpaths (meta pgno = 0) has LSN [483][34721].
 Berkeley DB error: end of log is [1][28]
 Berkeley DB error: /nix/var/nix/db/validpaths: unexpected file type or format</screen>
 
-or other weird Berkeley DB errors, and they don’t away (i.e.,
-automatic recovery doesn’t work).  This may be the case after a system crash.</para>
+or other weird Berkeley DB errors, and they don’t go away (i.e.,
+automatic recovery doesn’t work).  This may be the case after a system
+crash.</para>
 
 <para>Solution: first try to run <command>db_recover</command> and
 then <link linkend='refsec-nix-store-verify'><command>nix-store
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 90ebeaa79f..7009876f1b 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -465,7 +465,8 @@ void UserLock::release()
 static void runSetuidHelper(const string & command,
     const string & arg)
 {
-    string program = nixLibexecDir + "/nix-setuid-helper";
+    Path program = getEnv("NIX_SETUID_HELPER",
+        nixLibexecDir + "/nix-setuid-helper");
             
     /* Fork. */
     Pid pid;