diff --git a/src/Makefile.am b/src/Makefile.am
index 412e26f..62cb87d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -22,7 +22,7 @@ endif
 
 noinst_PROGRAMS = psl2c
 psl2c_SOURCES = psl2c.c
-psl2c_CPPFLAGS = -I$(top_srcdir)/include -D _GNU_SOURCE
+psl2c_CPPFLAGS = -I$(top_srcdir)/include
 if BUILTIN_GENERATOR_LIBICU
   psl2c_LDADD = -licuuc
 endif
diff --git a/src/psl.c b/src/psl.c
index 6fe0633..5280ec6 100644
--- a/src/psl.c
+++ b/src/psl.c
@@ -28,11 +28,6 @@
  *
  */
 
-/* need _GNU_SOURCE for qsort_r() */
-#ifndef _GNU_SOURCE
-#	define _GNU_SOURCE
-#endif
-
 #if HAVE_CONFIG_H
 # include <config.h>
 #endif