njplot-vib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/njplot-vib.c b/njplot-vib.c
index fe55609..63fd3b6 100644
--- a/njplot-vib.c
+++ b/njplot-vib.c
@@ -1976,7 +1976,7 @@ PDFONLY"       no window interface, just write the PDF/PostScript tree plot\n"
 #else
 		fprintf(stderr,
 #endif
-		message);
+		"%s", message);
 		exit(0);
 		}
 	}