diff -u -p xorg-cf-files-1.0.6.orig/gnu.cf xorg-cf-files-1.0.6/gnu.cf
--- xorg-cf-files-1.0.6.orig/gnu.cf	2021-01-04 12:47:28.399794000 +0100
+++ xorg-cf-files-1.0.6/gnu.cf	2021-01-04 12:49:14.978974000 +0100
@@ -21,7 +21,7 @@ XCOMM operating system:  OSName (OSMajor
 
 #define GNUSourceDefines      -D_POSIX_C_SOURCE=199309L \
                               -D_POSIX_SOURCE -D_XOPEN_SOURCE \
-                              -D_BSD_SOURCE -D_SVID_SOURCE
+                              -D_DEFAULT_SOURCE
 
 XCOMM XXXMB: What about _GNU_SOURCE, see Linux/UseInstalled?
 
diff -u -p xorg-cf-files-1.0.6.orig/linux.cf xorg-cf-files-1.0.6/linux.cf
--- xorg-cf-files-1.0.6.orig/linux.cf	2021-01-04 12:47:28.194801000 +0100
+++ xorg-cf-files-1.0.6/linux.cf	2021-01-04 12:49:59.493049000 +0100
@@ -232,7 +232,7 @@ InstallNamedTargetNoClobber(install,file
 #if LinuxCLibMajorVersion >= 6
 # define LinuxSourceDefines	-D_POSIX_C_SOURCE=199309L \
 				-D_POSIX_SOURCE -D_XOPEN_SOURCE \
-				-D_BSD_SOURCE -D_SVID_SOURCE \
+				-D_DEFAULT_SOURCE \
                                 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 \
 				LinuxAdditionalIncludes LinuxGnuSourceDefines \
 				LinuxLocaleDefines
@@ -251,7 +251,7 @@ InstallNamedTargetNoClobber(install,file
 # endif
 #else
 # define LinuxSourceDefines	-D_POSIX_SOURCE -D_POSIX_C_SOURCE=2 \
-				-D_BSD_SOURCE -D_SVID_SOURCE \
+				-D_DEFAULT_SOURCE \
 				LinuxGnuSourceDefines LinuxLocaleDefines
 # define XawI18nDefines		-DUSE_XWCHAR_STRING -DUSE_XMBTOWC
 # ifndef HasLibCrypt