diff --git a/include/osmocom/sim/sim.h b/include/osmocom/sim/sim.h
index d7c4242..ba6fb70 100644
--- a/include/osmocom/sim/sim.h
+++ b/include/osmocom/sim/sim.h
@@ -324,8 +324,6 @@
 
 /* CARD READERS */
 
-struct osim_reader_ops;
-
 enum osim_proto {
 	OSIM_PROTO_T0	= 0,
 	OSIM_PROTO_T1	= 1,
@@ -337,6 +335,13 @@
 	OSIM_READER_DRV_SERIAL = 2,
 };
 
+struct osim_reader_ops {
+	const char *name;
+	struct osim_reader_hdl *(*reader_open)(int idx, const char *name, void *ctx);
+	struct osim_card_hdl *(*card_open)(struct osim_reader_hdl *rh, enum osim_proto proto);
+	int (*transceive)(struct osim_reader_hdl *rh, struct msgb *msg);
+};
+
 struct osim_reader_hdl {
 	/*! \brief member in global list of readers */
 	struct llist_head list;