diff --git a/audio/gnaural/Makefile b/audio/gnaural/Makefile
index a0cfac3f14fb..5261fe17dc66 100644
--- a/audio/gnaural/Makefile
+++ b/audio/gnaural/Makefile
@@ -20,6 +20,7 @@ LIB_DEPENDS=	portaudio:${PORTSDIR}/audio/portaudio2 \
 		sndfile:${PORTSDIR}/audio/libsndfile
 
 GNU_CONFIGURE=	yes
+USE_CSTD=	gnu89
 USE_GNOME=	libglade2 desktopfileutils
 
 post-install: