diff --git a/gnu/packages/xorg.scm b/gnu/packages/xorg.scm
index bf7a4050a3..15ebd380d4 100644
--- a/gnu/packages/xorg.scm
+++ b/gnu/packages/xorg.scm
@@ -2402,6 +2402,18 @@ XC-APPGROUP, XTEST.")
         (base32
          "0xca343ff12wh6nsq76r0nbsfrm8dypjrzm4fqz9vv9v8i8kfrp1"))))
     (build-system gnu-build-system)
+    (arguments
+     `(#:phases (modify-phases %standard-phases
+                  (add-before 'configure 'pedantry
+                    (lambda _
+                      ;; XXX: libevdev includes kernel headers, which causes this
+                      ;; compile test to fail with:
+                      ;; ...-headers-4.14.67/include/asm-generic/posix_types.h:88:14:
+                      ;;error: ISO C90 does not support ‘long long’ [-Werror=long-long]
+                      (substitute* "test/Makefile.in"
+                        (("-pedantic -Werror -std=c89")
+                         "-pedantic -Werror -std=c99"))
+                      #t)))))
     (native-inputs `(("python" ,python)))
     (home-page "https://www.freedesktop.org/wiki/Software/libevdev/")
     (synopsis "Wrapper library for evdev devices")