diff --git a/sch2fig/main.c b/sch2fig/main.c
index 43fcdfc..7b284ae 100644
--- a/sch2fig/main.c
+++ b/sch2fig/main.c
@@ -95,6 +95,8 @@ int main(int argc, char *const *argv)
 		gfx_argv[1] = NULL;
 	} else {
 		gfx_argc = argc - dashdash - 1;
+		if (!gfx_argc)
+			usage(*argv);
 		gfx_argv = alloc_size(sizeof(const char *) * (gfx_argc + 1));
 		memcpy(gfx_argv, argv + dashdash + 1,
 		    sizeof(const char *) * (gfx_argc + 1));