diff --git a/texlive.changes b/texlive.changes
index 74c5584..ecda7ba 100644
--- a/texlive.changes
+++ b/texlive.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue Aug  1 07:53:05 UTC 2017 - schwab@suse.de
+
+- Define _GNU_SOURCE to request GNU extensions
+
 -------------------------------------------------------------------
 Wed Jun 28 07:56:00 UTC 2017 - nico.kruber@gmail.com
 
diff --git a/texlive.spec b/texlive.spec
index 6206881..208e4e5 100644
--- a/texlive.spec
+++ b/texlive.spec
@@ -3269,11 +3269,7 @@ This package is required by the package texlive-biber-bin.
 %endif
     CC=gcc
     CXX=g++
-    if grep -q _DEFAULT_SOURCE /usr/include/features.h ; then
-	XCFLAGS="$RPM_OPT_FLAGS -D_POSIX_C_SOURCE=200803L -D_XOPEN_SOURCE=600 -D_DEFAULT_SOURCE"
-    else
-	XCFLAGS="$RPM_OPT_FLAGS -D_POSIX_C_SOURCE=200803L -D_XOPEN_SOURCE=600 -D_BSD_SOURCE"
-    fi
+    XCFLAGS="$RPM_OPT_FLAGS -D_GNU_SOURCE"
     XCXXFLAGS="$XCFLAGS"
     cflags ()
     {