diff --git a/Formula/m/mandoc.rb b/Formula/m/mandoc.rb
index 96d2155cba338..bf6c206dfd18d 100644
--- a/Formula/m/mandoc.rb
+++ b/Formula/m/mandoc.rb
@@ -90,6 +90,7 @@ def install
     ENV.deparallelize do
       system "make"
       system "make", "install"
+      system "make", "lib-install"
     end
   end