diff --git a/Process.c b/Process.c
index 54c41af4..420311dc 100644
--- a/Process.c
+++ b/Process.c
@@ -8,6 +8,8 @@ in the source distribution for its full text.
 #include "Process.h"
 #include "Settings.h"
 
+#include "config.h"
+
 #include "CRT.h"
 #include "StringUtils.h"
 #include "RichString.h"
diff --git a/configure.ac b/configure.ac
index ffd8fede..4c7360e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,7 +69,7 @@ dnl glibc 2.25 deprecates 'major' and 'minor' in <sys/types.h> and requires to
 dnl include <sys/sysmacros.h>. However the logic in AC_HEADER_MAJOR has not yet
 dnl been updated in Autoconf 2.69, so use a workaround:
 m4_version_prereq([2.70], [],
-[if test "x$ac_cv_header_sys_mkdev_h" = xno; then
+[if test "x$ac_cv_header_sys_mkdev_h" != xyes; then
    AC_CHECK_HEADER(sys/sysmacros.h, [AC_DEFINE(MAJOR_IN_SYSMACROS, 1,
       [Define to 1 if `major', `minor', and `makedev' are declared in <sys/sysmacros.h>.])])
 fi])