diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index d8f2fe6d7..723db71fd 100755
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -174,7 +174,7 @@ static void _main(int argc, char * * argv)
         else if (*arg == "--run-env") // obsolete
             runEnv = true;
 
-        else if (*arg == "--command" || *arg == "--run") {
+        else if (runEnv && (*arg == "--command" || *arg == "--run")) {
             if (*arg == "--run")
                 interactive = false;
             envCommand = getArg(*arg, arg, end) + "\nexit";