diff --git a/cmake/Libraries.cmake b/cmake/Libraries.cmake
index 0b654bbc3..77aa4403f 100644
--- a/cmake/Libraries.cmake
+++ b/cmake/Libraries.cmake
@@ -257,8 +257,6 @@ macro(configure_xorg_libs)
                       HAVE_X11_EXTENSIONS_DPMS_H)
   check_include_files("X11/extensions/Xinerama.h"
                       HAVE_X11_EXTENSIONS_XINERAMA_H)
-  check_include_files("${XKBlib};X11/extensions/XKBstr.h"
-                      HAVE_X11_EXTENSIONS_XKBSTR_H)
   check_include_files("X11/extensions/XKB.h" HAVE_XKB_EXTENSION)
   check_include_files("X11/extensions/XTest.h" HAVE_X11_EXTENSIONS_XTEST_H)
   check_include_files("${XKBlib}" HAVE_X11_XKBLIB_H)
diff --git a/src/lib/config.h.in b/src/lib/config.h.in
index 72ab67043..e36f63397 100644
--- a/src/lib/config.h.in
+++ b/src/lib/config.h.in
@@ -89,9 +89,6 @@
 /* Define to 1 if you have the <X11/extensions/Xinerama.h> header file. */
 #cmakedefine HAVE_X11_EXTENSIONS_XINERAMA_H @HAVE_X11_EXTENSIONS_XINERAMA_H@
 
-/* Define to 1 if you have the <X11/extensions/XKBstr.h> header file. */
-#cmakedefine HAVE_X11_EXTENSIONS_XKBSTR_H @HAVE_X11_EXTENSIONS_XKBSTR_H@
-
 /* Define to 1 if you have the <X11/extensions/XTest.h> header file. */
 #cmakedefine HAVE_X11_EXTENSIONS_XTEST_H @HAVE_X11_EXTENSIONS_XTEST_H@