--- i3-4.15/testcases/lib/i3test/XTEST.pm.old	2018-09-27 16:18:59.682101063 -0700
+++ i3-4.15/testcases/lib/i3test/XTEST.pm	2018-09-27 16:20:33.723493893 -0700
@@ -39,6 +39,7 @@
 my %sn_config;
 BEGIN {
     %sn_config = ExtUtils::PkgConfig->find('xcb-xkb xcb-xtest xcb-util');
+    $sn_config{cflags} .= ' -D_GNU_SOURCE';
 }
 
 use Inline C => Config => LIBS => $sn_config{libs}, CCFLAGS => $sn_config{cflags};
--- i3-4.15/testcases/t/175-startup-notification.t.old	2018-09-27 16:24:17.546808884 -0700
+++ i3-4.15/testcases/t/175-startup-notification.t	2018-09-27 16:24:55.587372292 -0700
@@ -31,11 +31,13 @@
 my %sn_config;
 BEGIN {
     %sn_config = ExtUtils::PkgConfig->find('libstartup-notification-1.0');
+    $sn_config{cflags} .= ' -D_GNU_SOURCE';
 }
 
 use Inline C => Config => LIBS => $sn_config{libs}, CCFLAGS => $sn_config{cflags};
 use Inline C => <<'END_OF_C_CODE';
 
+#include <sys/types.h>
 #include <xcb/xcb.h>
 
 #define SN_API_NOT_YET_FROZEN 1