diff --git a/src/nix/build.cc b/src/nix/build.cc
index bd0c8862b..d28aabba9 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -50,6 +50,7 @@ struct CmdBuild : InstallablesCommand, MixOutLinkByDefault, MixDryRun, MixJSON,
     {
         addFlag({
             .longName = "print-out-paths",
+            .shortName = 'P',
             .description = "Print the resulting output paths",
             .handler = {&printOutputPaths, true},
         });