diff --git a/libX11.changes b/libX11.changes
index 3bdebac..ce34678 100644
--- a/libX11.changes
+++ b/libX11.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Sat Nov  5 01:23:00 UTC 2016 - jengelh@inai.de
+
+- Run fdupes over at least the manpages
+
 -------------------------------------------------------------------
 Sat Oct 29 00:10:49 UTC 2016 - tobias.johannes.klausmann@mni.thm.de
 
diff --git a/libX11.spec b/libX11.spec
index 30b0475..13f6c9b 100644
--- a/libX11.spec
+++ b/libX11.spec
@@ -38,6 +38,7 @@ Patch15:        en-locales.diff
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  autoconf >= 2.60
 BuildRequires:  automake
+BuildRequires:  fdupes
 BuildRequires:  libtool
 BuildRequires:  pkgconfig
 BuildRequires:  pkgconfig(inputproto)
@@ -168,7 +169,7 @@ for i in *.UTF-8; do
 done
 popd
 
-# fdupes %buildroot/%_prefix
+%fdupes %buildroot/%_mandir
 
 %post   -n libX11-6 -p /sbin/ldconfig