diff --git a/textproc/libdiff/Makefile b/textproc/libdiff/Makefile
index 508362717cb0..66bfcbbf4652 100644
--- a/textproc/libdiff/Makefile
+++ b/textproc/libdiff/Makefile
@@ -13,4 +13,6 @@ PLIST_FILES=	lib/libdiff.a \
 		man/man3/diff.3.gz
 HAS_CONFIGURE=	yes
 
+CONFIGURE_ARGS=	PREFIX=${PREFIX}
+
 .include <bsd.port.mk>