diff --git a/mathgl-2.3-x11.patch b/mathgl-2.3-x11.patch
new file mode 100644
index 0000000..4354cf6
--- /dev/null
+++ b/mathgl-2.3-x11.patch
@@ -0,0 +1,11 @@
+--- udav/CMakeLists.txt.orig	2015-03-21 14:42:01.325397847 +0600
++++ udav/CMakeLists.txt	2015-03-21 14:42:15.145923191 +0600
+@@ -38,7 +38,7 @@ endif(enable-qt5)
+ add_executable(udav ${udav_src} ${udav_moc_src} ${udav_rc_src})
+ #set_target_properties(udav PROPERTIES COMPILE_FLAGS "${CMAKE_CXX_FLAGS} -pthread")
+ if(enable-qt5)
+-	target_link_libraries(udav mgl-qt5)
++	target_link_libraries(udav mgl-qt5 X11)
+ 	qt5_use_modules(udav Core Widgets Gui PrintSupport)
+ else(enable-qt5)
+ 	target_link_libraries(udav mgl-qt4)
diff --git a/mathgl.spec b/mathgl.spec
index c81c6c7..f03e90e 100644
--- a/mathgl.spec
+++ b/mathgl.spec
@@ -5,7 +5,7 @@
 
 Name:          mathgl
 Version:       2.3
-Release:       5%{?dist}
+Release:       6%{?dist}
 Summary:       Cross-platform library for making high-quality scientific graphics
 Summary(de):   Plattformübergreifende Bibliothek für hochwertige wissenschaftliche Graphiken
 Summary(ru):   Библиотека для осуществления высококачественной визуализации данных
@@ -29,6 +29,9 @@ Patch3:        mathgl-2.3-fltk-skip-fluid.patch
 # No qt4 and qt5 simultaneously. There are some issues with Qt5, leave v.4
 Patch4:        mathgl-2.3-no_qt4.patch
 
+# Fix linking with libX11
+Patch5:        mathgl-2.3-x11.patch
+
 Requires:      %{name}-common = %{version}-%{release}
 
 # mandatory packages
@@ -184,7 +187,8 @@ done
 %patch1 -b .examples
 %patch2 -b .no_octave
 %patch3 -b .fluid
-%patch4 -b .no_qt4_qt5
+%patch4 -b .no_qt4
+%patch5 -b .qt5
 
 # Fix hardcoded paths
 sed -i s,/usr/local/share/doc/mathgl/,%{_docdir}/%{name}/, udav/udav_wnd.h
@@ -366,6 +370,9 @@ fi
 %{_includedir}/mpich-%{_arch}/mgl2/
 
 %changelog
+* Sat Mar 21 2015 Dmitrij S. Kryzhevich <krege@land.ru> - 2.3-6
+- Fix linking with libX11.
+
 * Tue Mar 17 2015 Dmitrij S. Kryzhevich <krege@land.ru> - 2.3-5
 - Rebuild for new mpich.