diff --git a/src/drivers/pc80/vga/vga.c b/src/drivers/pc80/vga/vga.c
index 9961e3f59d..3471c944a1 100644
--- a/src/drivers/pc80/vga/vga.c
+++ b/src/drivers/pc80/vga/vga.c
@@ -262,6 +262,9 @@ vga_frame_set(unsigned int line, unsigned int character)
 void
 vga_line_write(unsigned int line, const char *string)
 {
+	if (!string)
+		return;
+
 	unsigned short *p = (unsigned short *)VGA_FB + (VGA_COLUMNS * line);
 	size_t i, len = strlen(string);