diff --git a/options.c b/options.c
index 7135231..354067d 100644
--- a/options.c
+++ b/options.c
@@ -575,6 +575,19 @@
 	return 0;
 }
 
+static int rw_verify(struct fio_option *o, void *data)
+{
+	struct thread_data *td = data;
+
+	if (read_only && td_write(td)) {
+		log_err("fio: job <%s> has write bit set, but fio is in"
+			" read-only mode\n", td->o.name);
+		return 1;
+	}
+
+	return 0;
+}
+
 #define __stringify_1(x)	#x
 #define __stringify(x)		__stringify_1(x)
 
@@ -648,6 +661,7 @@
 		.off1	= td_var_offset(td_ddir),
 		.help	= "IO direction",
 		.def	= "read",
+		.verify	= rw_verify,
 		.posval = {
 			  { .ival = "read",
 			    .oval = TD_DDIR_READ,