diff --git a/package/gluon-radv-filterd/src/Makefile b/package/gluon-radv-filterd/src/Makefile
index 82a2bace..87000139 100644
--- a/package/gluon-radv-filterd/src/Makefile
+++ b/package/gluon-radv-filterd/src/Makefile
@@ -1,7 +1,9 @@
 all: gluon-radv-filterd respondd.so
 
+CPPFLAGS += -D_GNU_SOURCE
+
 gluon-radv-filterd: gluon-radv-filterd.c
 	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -Wall -o $@ $^ $(LDLIBS)
 
 respondd.so: respondd.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -shared -fPIC -D_GNU_SOURCE -o $@ $^ $(LDLIBS) -lgluonutil
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -shared -fPIC -o $@ $^ $(LDLIBS) -lgluonutil
diff --git a/package/gluon-radv-filterd/src/gluon-radv-filterd.c b/package/gluon-radv-filterd/src/gluon-radv-filterd.c
index 18d6f303..3aae38d0 100644
--- a/package/gluon-radv-filterd/src/gluon-radv-filterd.c
+++ b/package/gluon-radv-filterd/src/gluon-radv-filterd.c
@@ -23,7 +23,6 @@
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#define _GNU_SOURCE
 #include <errno.h>
 #include <signal.h>
 #include <stdarg.h>