diff --git a/doc/manual/advanced-topics/distributed-builds.xml b/doc/manual/advanced-topics/distributed-builds.xml
index 70f396f81..032455bd3 100644
--- a/doc/manual/advanced-topics/distributed-builds.xml
+++ b/doc/manual/advanced-topics/distributed-builds.xml
@@ -44,7 +44,8 @@ outputs and perform the remote build.  To use it, you should set
 <envar>NIX_BUILD_HOOK</envar> to
 <filename><replaceable>prefix</replaceable>/libexec/nix/build-remote.pl</filename>.
 You should also define a list of available build machines and point
-the environment variable <envar>NIX_REMOTE_SYSTEMS</envar> to it.  An
+the environment variable <envar>NIX_REMOTE_SYSTEMS</envar> to it (the
+path has to be absolute, otherwise nix will fail to distribute the build).  An
 example configuration is shown in <xref linkend='ex-remote-systems'
 />.  Each line in the file specifies a machine, with the following
 bits of information: